Cam-actuated split blade housing for power operated rotary knife

ABSTRACT

A blade housing assembly for a power operated rotary knife including a split blade housing and a cam mechanism for changing a blade housing diameter between blade supporting and blade changing positions. The split blade housing includes an annular blade support section, a mounting section and a split extending through the mounting section and an inner wall of the blade support section and defining a split distance between first and second circumferential ends of the inner wall. The split includes a radial split section and an angled split section adjacent the inner wall. The mounting section includes first and second body portions on opposite sides of the split. The cam mechanism includes a cam plate bridging the first and second body portions and a cam member rotatably supported by the cam plate. The cam member is rotatable between closed and open positions to change the blade housing diameter.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part application ofco-pending U.S. application Ser. No. 15/822,914, filed Nov. 27, 2017 andentitled CAM-ACTUATED SPLIT BLADE HOUSING FOR POWER OPERATED ROTARYKNIFE, which is a continuation-in-part application Ser. No. 15/374,207,filed Dec. 9, 2016 and entitled POWER OPERATED ROTARY KNIFE. The presentapplication claims priority from application Ser. No. 15/822,914 andfrom application Ser. No. 15/374,207, which are fully incorporatedherein in their respective entireties, by reference, for any and allpurposes.

TECHNICAL FIELD

The present disclosure relates to a power operated rotary knife and,more specifically, to a split blade housing assembly for a poweroperated rotary knife that includes a split blade housing and atwo-position cam mechanism that, in a first, closed position of the cammechanism, holds or secures the split blade housing in a first,blade-supporting position, and, in a second, open position of the cammechanism, secures the split blade housing in a second, blade changingposition.

BACKGROUND

Hand held, power operated rotary knives are widely used in meatprocessing facilities for meat cutting and trimming operations. Poweroperated rotary knives also have application in a variety of otherindustries where cutting and/or trimming operations need to be performedquickly and with less effort than would be the case if traditionalmanual cutting or trimming tools were used, e.g., long knives, scissors,nippers, etc. By way of example, power operated rotary knives may beeffectively utilized for such diverse tasks as tissue harvesting orrecovery, debriding/removal of skin tissue, bone tissue, tendon/ligamentharvesting from human or animal tissue donors for medical purposes.Power operated rotary knives may also be used for taxidermy and forcutting and trimming of elastomeric or urethane foam for a variety ofapplications including vehicle seats.

Power operated rotary knives typically include a handle assembly and ahead assembly attachable to the handle assembly. The head assemblyincludes an annular blade housing and an annular rotary knife bladesupported for rotation by the blade housing. The annular rotary blade ofconventional power operated rotary knives is typically rotated by adrive assembly which include a flexible shaft drive assembly extendingthrough an opening in the handle assembly. The shaft drive assemblyengages and rotates a pinion gear supported by the head assembly. Theflexible shaft drive assembly includes a stationary outer sheath and arotatable interior drive shaft which is driven by an electric motor.Alternatively, the pinion gear may be driven by a pneumatic motormounted within the handle assembly. Gear teeth of the pinion gear engagemating gear teeth formed on an upper surface of the rotary knife blade.

Upon rotation of the pinion gear by the drive shaft of the flexibleshaft drive assembly, the annular rotary blade rotates within the bladehousing at a high RPM, on the order of 900-1900 RPM, depending on thestructure and characteristics of the drive assembly including the motor,the shaft drive assembly, and a diameter and the number of gear teethformed on the rotary knife blade. Power operated rotary knives aredisclosed in U.S. Pat. No. 6,354,949 to Bans et al., U.S. Pat. No.6,751,872 to Whited et al., U.S. Pat. No. 6,769,184 to Whited, U.S. Pat.No. 6,978,548 to Whited et al., U.S. Pat. No. 8,448,340 to Whited, andU.S. Pat. No. 8,726,524 to Whited et al., all of which are assigned tothe assignee of the present invention and all of which are incorporatedherein in their respective entireties by reference.

SUMMARY

In one aspect, the present disclosure relates to a blade housingassembly for supporting an annular rotary knife blade of a poweroperated rotary knife for rotation about a central axis of rotation, theblade housing assembly comprising: a split blade housing including: anannular blade support section centered about a blade housing center lineand including an inner wall; a mounting section extending from the bladesupport section; and a split extending through the mounting section andthe inner wall of the blade support section and defining a splitdistance between first and second circumferential ends of the innerwall; the mounting section including a first body portion and a secondbody portion on opposite sides of the split, the first body portionincluding a first cam slot having a first end portion and a spaced apartsecond end portion; and a cam mechanism including: a cam plate bridgingthe first and second body portions of the mounting section of the splitblade housing; and a cam member rotatably supported by the cam plate,the cam member rotatable between a first, closed position and a second,open position and including a first cam pin received in the first camslot of the first body portion of the mounting section of the splitblade housing, in the first, closed position of the cam member, thefirst cam pin is positioned nearer the first end portion of the firstcam slot and the split distance between the first and secondcircumferential ends of the inner wall being a first value, in thesecond, open position of the cam member, the first cam pin is positionednearer the second end portion of the first cam slot and the splitdistance between the first and second circumferential ends of the innerwall being a second value.

In another aspect, the present disclosure relates to a blade housingassembly for supporting an annular rotary knife blade of a poweroperated rotary knife for rotation about a central axis of rotation, theblade housing assembly comprising: a split blade housing including: anannular blade support section centered about a blade housing centerline, an inner wall of the blade support section defining a bladebearing region; a mounting section extending from the blade supportsection; and a split extending through the mounting section and theinner wall of the blade support section and defining a split distancebetween first and second circumferential ends of the inner wall; themounting section including a first body portion and a second bodyportion on opposite sides of the split, the first body portion includinga first cam slot having a first end portion and a spaced apart secondend portion and the second body portion including a second cam slothaving a first end portion and a spaced apart second end portion; and acam mechanism including: a cam plate bridging the first and second bodyportions of the mounting section of the split blade housing; and a cammember rotatably supported by the cam plate, the cam member rotatablebetween a first, closed position and a second, open position andincluding a first cam pin received in the first cam slot of the firstbody portion of the mounting section of the split blade housing and asecond cam pin received in the second cam slot of the second bodyportion of the mounting section of the split blade housing, in thefirst, closed position of the cam member, the first cam pin ispositioned nearer the first end portion of the first cam slot, thesecond cam pin is positioned nearer the first end portion of the secondcam slot and the split distance between the first and secondcircumferential ends of the inner wall being a first value, in thesecond, open position of the cam member, the first cam pin is positionednearer the second end portion of the first cam slot, the second cam pinis positioned nearer the second end portion of the second cam slot andthe split distance between the first and second circumferential ends ofthe inner wall being a second value.

In another aspect, the present invention relates to a power operatedrotary knife comprising: power operated rotary knife comprising: anannular rotary knife blade supported for rotation about a central axisof rotation; an elongated handle assembly extending along a longitudinalaxis; a frame body coupled to a distal end of the elongated handleassembly, the frame body including a mounting pedestal; and a bladehousing assembly coupled to the frame body and supporting the annularrotary knife blade for rotation about the central axis of rotation, theblade housing assembly including: a split blade housing including: anannular blade support section centered about a blade housing center lineand including an inner wall; a mounting section extending from the bladesupport section; and a split extending through the mounting section andthe inner wall of the blade support section and defining a splitdistance between first and second circumferential ends of the innerwall; the mounting section including a first body portion and a secondbody portion on opposite sides of the split, the first body portionincluding a first cam slot having a first end portion and a spaced apartsecond end portion; and a cam mechanism including: a cam plate bridgingthe first and second body portions of the mounting section of the splitblade housing; and a cam member rotatably supported by the cam plate,the cam member rotatable between a first, closed position and a second,open position and including a first cam pin received in the first camslot of the first body portion of the mounting section of the splitblade housing, in the first, closed position of the cam member, thefirst cam pin is positioned nearer the first end portion of the firstcam slot and the split distance between the first and secondcircumferential ends of the inner wall being a first value, in thesecond, open position of the cam member, the first cam pin is positionednearer the second end portion of the first cam slot and the splitdistance between the first and second circumferential ends of the innerwall being a second value, the cam mechanism securing the mountingsection of the split blade housing to the mounting pedestal of the framebody.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the presentdisclosure will become apparent to one skilled in the art to which thepresent disclosure relates upon consideration of the followingdescription of the disclosure with reference to the accompanyingdrawings, wherein like reference numerals, unless otherwise describedrefer to like parts throughout the drawings and in which:

FIG. 1 is a schematic top, front perspective section view of a sixthexemplary embodiment of a power operated rotary knife of the presentdisclosure, including a head assembly, a handle assembly and a drivemechanism, the head assembly including a frame body, an annular rotaryknife blade and a blade housing assembly supporting the annular rotaryknife blade for rotation, the blade housing assembly including anannular split ring blade housing and a cam mechanism coupled to theblade housing to selectively move the blade housing between a first,blade supporting position and a second, blade changing position;

FIG. 2 is a schematic bottom, front perspective view of the poweroperated rotary knife of FIG. 1;

FIG. 3 is a schematic top plan view of the power operated rotary knifeof FIG. 1;

FIG. 4 is a schematic bottom plan view of the power operated rotaryknife of FIG. 1;

FIG. 5 is a schematic side elevation view of the power operated rotaryknife of FIG. 1;

FIG. 6 is a schematic vertical section view taken along a longitudinalaxis of the handle assembly of the power operated rotary knife of FIG.1;

FIG. 7 is a schematic enlarged vertical section view of the poweroperated rotary knife of FIG. 1 which is within a circle labeled FIG. 7in FIG. 6;

FIG. 8 is a schematic exploded, top, front perspective view of the poweroperated rotary knife of FIG. 1;

FIG. 9 is a schematic exploded, bottom, front perspective view of thepower operated rotary knife of FIG. 1;

FIG. 10 is a schematic bottom plan view of the annular split ring bladehousing of the power operated rotary knife of FIG. 1;

FIG. 11 is a schematic top plan view of the annular split ring bladehousing of FIG. 10;

FIG. 12 is a schematic front elevation view of the cam mechanism of thepower operated rotary knife of FIG. 1;

FIG. 13 is a schematic top plan view of the cam mechanism of FIG. 12;

FIG. 14 is a schematic bottom plan view of the cam mechanism of FIG. 12;

FIG. 15 is a schematic vertical section view of the cam mechanism ofFIG. 12 as seen from a plane indicated by the line 15-15 in FIG. 14;

FIG. 16 is a schematic front elevation view of a cam member of the cammechanism of FIG. 12;

FIG. 17 is a schematic top plan view of the cam member of FIG. 16;

FIG. 18 is a schematic bottom plan view of the cam member of FIG. 16;

FIG. 19 is a schematic top plan view of a cam plate of the cam mechanismof FIG. 12;

FIG. 20 is a schematic rear elevation view of the cam plate of FIG. 19;

FIG. 21 is a schematic bottom plan view of the power operated rotaryknife of FIG. 1 with the annular rotary knife blade removed and a camplate of the cam mechanism of the blade housing assembly removed andwith the cam mechanism in a first, closed position and the annular splitblade housing in the first, blade supporting position;

FIG. 22 is a schematic enlarged bottom plan view of a portion of thepower operated rotary knife of FIG. 1 which is within a circle labeledFIG. 22 in FIG. 21, with the cam mechanism in the first, closed positionand the annular split blade housing in the first, blade supportingposition;

FIG. 23 is a schematic bottom plan view of the power operated rotaryknife of FIG. 31 with the annular rotary knife blade removed and a camplate of the cam mechanism of the blade housing assembly removed andwith the cam mechanism in a second, open position and the annular splitblade housing in the second, blade changing position;

FIG. 24 is a schematic enlarged bottom plan view of a portion of thepower operated rotary knife of FIG. 1 which is within a circle labeledFIG. 24 in FIG. 23 and with the cam mechanism in the second, openposition and the annular split blade housing in the second, bladechanging position;

FIG. 25 is a schematic section view the annular split ring blade housingof FIG. 10 as seen from a plane indicated by the line 25-25 in FIG. 10;and

FIG. 26 is a schematic top, front perspective section view of a seventhexemplary embodiment of a power operated rotary knife of the presentdisclosure, including a head assembly, a handle assembly and a drivemechanism, the head assembly including a frame body, an annular rotaryknife blade and a blade housing assembly supporting the annular rotaryknife blade for rotation, the blade housing assembly including anannular split ring blade housing and a cam mechanism coupled to theblade housing to selectively move the blade housing between a first,blade supporting position and a second, blade changing position;

FIG. 27 is a schematic bottom, front perspective view of the poweroperated rotary knife of FIG. 26;

FIG. 28 is a schematic bottom plan view of the power operated rotaryknife of FIG. 26;

FIG. 29 is a schematic side elevation view of the power operated rotaryknife of FIG. 26;

FIG. 30 is a schematic vertical section view taken along a longitudinalaxis of the handle assembly of the power operated rotary knife of FIG.26;

FIG. 31 is a schematic enlarged vertical section view of the poweroperated rotary knife of FIG. 1 which is within a circle labeled FIG. 31in FIG. 30;

FIG. 32 is a schematic exploded, top, front perspective view of thepower operated rotary knife of FIG. 26;

FIG. 33 is a schematic exploded, bottom, front perspective view of thehead assembly of the power operated rotary knife of FIG. 26;

FIG. 34 is a schematic bottom plan view of the head assembly of thepower operated rotary knife of FIG. 26, with the cam mechanism in afirst, closed or locked position;

FIG. 35 is a schematic bottom plan view of the head assembly of FIG. 34with a cam plate of the cam mechanism being removed;

FIG. 36 is a schematic top plan view of the annular split ring bladehousing of the blade housing assembly of the power operated rotary knifeof FIG. 26, with the blade housing in the first, blade supportingposition;

FIG. 37 is a schematic vertical section view of the annular split ringblade housing of FIG. 36, as seen from a plane indicated by the line37-37 in FIG. 36;

FIG. 38 is a schematic longitudinal vertical section view of the annularsplit ring blade housing of FIG. 36, as seen from a plane indicated bythe line 38-38 in FIG. 36;

FIG. 39 is a schematic top plan view of the annular split ring bladehousing of FIG. 36 which is within a circle labeled FIG. 39 in FIG. 36;

FIG. 40 is a schematic top plan view of the cam mechanism of the bladehousing assembly of the power operated rotary knife of FIG. 26, with thecam mechanism in the first, closed or locked position;

FIG. 41 is a schematic top plan view of the cam mechanism of the bladehousing assembly of the power operated rotary knife of FIG. 26, with thecam mechanism in a second, open or unlocked position;

FIG. 42 is a schematic bottom plan view of the blade housing assembly ofthe power operated rotary knife of FIG. 26, with the cam mechanism inthe first, closed or locked position first, closed or locked positionand the annular split ring blade housing in the first, blade supportingposition;

FIG. 43 is a schematic bottom plan view of the blade housing assembly ofthe power operated rotary knife of FIG. 26, with the cam mechanism in asecond, open or unlocked position and the annular split ring bladehousing in the second, blade changing position;

FIG. 44 is a schematic top, front perspective view of a cam member ofthe cam mechanism of the blade housing assembly of the power operatedrotary knife of FIG. 26;

FIG. 45 is a schematic bottom, front perspective view of the cam memberof FIG. 44;

FIG. 46 is a schematic front elevation view of the cam member of FIG. 44as seen from a plane indicated by the line 46-46 in FIG. 40;

FIG. 47 is a schematic top, front perspective view of a cam plate of thecam mechanism of the blade housing assembly of the power operated rotaryknife of FIG. 26; and

FIG. 48 is a bottom, front perspective view of the cam plate of FIG. 47.

DETAILED DESCRIPTION

The descriptions and disclosures, including drawings, relating to handheld, power operated rotary knives 100, 1000, 2000 and 3000, of thefirst, second, third and fourth exemplary embodiments, and componentsand assemblies thereof, and the rotary knife blade—blade housingassembly 4500 of the fifth exemplary embodiment, and components thereof,as disclosed in parent U.S. application Ser. No. 15/374,207 (hereinafter“the '207 application”), filed Dec. 9, 2016 and entitled POWER OPERATEDROTARY KNIFE, assigned to the assignee of the present application, arehereby fully incorporated herein by reference in their respectiveentireties by reference. For brevity, the descriptions of the poweroperated rotary knives will not be repeated herein.

Sixth Embodiment—Power Operated Rotary Knife 6000

A sixth exemplary embodiment of a power operated rotary knife of thepresent disclosure is shown generally at 6000 in FIGS. 1-9. The poweroperated rotary knife 6000 extends between a distal or forward end 6001and a proximal or rearward end 6002 of the power operated rotary knife6000. The power operated rotary knife 6000 includes an elongated handleassembly 6110, a head assembly, which is releasably secured to a frontor distal end 6112 of the handle assembly 6110, and a drive mechanism6600, including a gear train 6604. The handle assembly 6110 includes acentral throughbore 6115 that extends along a central longitudinal axisLA of the handle assembly 6110. The head assembly 6200 extends from thehandle assembly 6110 along the central longitudinal axis LA in a forwardor distal direction FW. The throughbore 6115 of the handle assembly 6110receives a distal portion of a flexible drive shaft assembly (similar tothe flexible drive shaft assembly 700 of the first exemplary embodiment)which rotates the drive mechanism 6600, as described in the firstexemplary embodiment of the '207 application. As used herein, theforward direction FW will be a direction extending generally along orparallel to the handle assembly longitudinal axis toward the distal end6001 of the power operated rotary knife 6000 and a rearward direction RWwill be a direction extending generally along or parallel to the handleassembly longitudinal axis toward the proximal end 6002 of the poweroperated rotary knife 6000.

As best seen in FIGS. 8 and 9, the head assembly 6200 includes a framebody 6250 including a forward portion 6251 and a rearward portion 6280.The rearward portion 6280 of the frame body 6250 includes an annularboss 6282 that defines a mounting structure that receives and engagesthe front end 6112 of the handle assembly 6110 to secure the headassembly 6200 to the handle assembly 6110. The head assembly 6200further includes an annular rotary knife blade 6300, substantiallysimilar to the annular rotary knife blade 2300 of the power operatedrotary knife 2000 of the third exemplary embodiment of the '207application, and a blade housing assembly 6700 including a split bladehousing 6800 which supports the annular rotary knife blade 6300 forrotation about a central axis of rotation R. The annular rotary knifeblade 6300 includes an upper body 6310 and a lower blade section 6360extending from the body 6310. The annular rotary knife blade 6300 isrotatably driven by the drive mechanism 6600, as previously described.The forward portion 6251 of the frame body 6250 supports the drivemechanism 6600 and positions a gear head 6614 of a pinion gear 6610 ofthe gear train 6604 of the drive mechanism 6600 to interface with adriven gear 6340 of the body 6310 of the rotary knife blade 6300 tothereby rotate the blade 6300 about its central axis of rotation R.

As best seen in FIGS. 6 and 7, an assembled blade-blade housingcombination 6500 includes the annular rotary knife blade 6300 and thesplit blade housing 6800 supporting the rotary knife blade 6300 forrotation about the annular rotary knife blade's central axis of rotationR. The assembled blade-blade housing combination 6500 includes ablade-blade housing bearing structure 6550, similar to the blade-bladehousing bearing structure 2550 of the assembled blade-blade housingcombination 2500 of the third exemplary embodiment of the '207application. More specifically, the blade-blade housing bearingstructure 6550 includes two axially spaced apart bearing structures,namely, a first blade-blade housing bearing structure 6560 and a secondblade-blade housing bearing structure 6570.

Various components and assemblies of the power operated rotary knife6000 are substantially similar in structure and/or function tocorresponding components and assemblies of the power operated rotaryknife 2000 of the third exemplary embodiment of the '207 application. Inthe interest of brevity, components and assemblies of the power operatedrotary knife 6000 that are similar to the corresponding components andassemblies of the power operated rotary knife 2000 of the thirdexemplary embodiment in structure and/or function will not be fullydescribed herein. Instead, reference is made to the description of suchcomponents and assemblies set forth above in connection with the poweroperated rotary knife 2000 and/or the power operated rotary knife 100 ofthe first exemplary embodiment and/or the power operated rotary knife1000 of the second exemplary embodiment and/or the power operated rotaryknife 3000 of the fourth exemplary embodiment and/or the blade-bladehousing combination 4500 of the fifth exemplary embodiment, as set forthin the '207 application. Materials/fabrication of components andassemblies of the power operated rotary knife 6000 are similar tomaterials/fabrication of corresponding components and assemblies of thepower operated rotary knives 100, 1000, 2000, 3000 and the blade-bladehousing combination 4500, as described in the '207 application. Suchdescriptions of components and assemblies of the power operated rotaryknives 100, 1000, 2000, 3000 and the blade-blade housing combination4500 are hereby incorporated by reference from the '207 application inthe following description of the power operated rotary knife 6000 of thesixth exemplary embodiment. Identification of axes, lines, planes anddirections for the power operated rotary knife 6000, as set forthherein, will be the same as used for the description of the poweroperated rotary knives 100, 1000, 2000, 3000 in the '207 application.

Unique to the sixth exemplary embodiment of the power operated rotaryknife 6000 is a blade housing assembly 6700 of the head assembly 6200which functions to secure the rotary knife blade 6300 for rotation aboutthe central axis of rotation R. As best seen in FIGS. 21-24, the bladehousing assembly 6700 includes the split blade housing 6800 and a cammechanism or cam assembly 6900 affixed to the split blade housing 6800which, in a first, closed, locked or home position 6998 of the cammechanism 6900, secures the blade housing 6800 in a first, bladesupporting position 6898, characterized by a first, unexpanded or bladesupporting blade housing diameter BHD1 (depicted schematically in FIG.21), and, in a second, open, unlocked or expanded position 6999 of thecam mechanism 6900, secures the blade housing 6800 in a second, bladechanging position 6899, characterized by a second, expanded bladehousing diameter BHD2 (FIG. 23). The blade housing 6800 includes anannular blade support section 6850 which supports the rotary knife blade6300 for rotation and a mounting section 6802, which may be consideredas a tongue or projection extending radially outwardly and in agenerally rearward direction RW from the annular blade support section6850.

The first and second blade housing diameters BHD1, BHD2 are measuredwith respect to the outer diameter of the annular blade support section6850 in a direction generally orthogonal to the handle assemblylongitudinal axis LA. It is to be understood, of course, that the secondblade housing diameter BHD2 is larger than the first blade housingdiameter BHD1 to facilitate removal of the annular rotary knife blade6300 from the split blade housing 6800 when the blade housing 6800 is inthe second, blade changing position 6899. It being further understoodthat the bearing interface between a blade bearing region 6320 of theannular rotary knife blade 6300 and a blade housing bearing region 6860of the blade support section 6850 of the blade housing 6800 togethercomprising the blade-blade housing structure 6550 of the power operatedrotary knife 6000 support the blade 6300 for rotation about its centralaxis of rotation R. When the blade housing diameter moves from thefirst, unexpanded blade housing diameter BHD1 to the second, expandedblade housing diameter BHD2, a diameter of a bearing region 6860 of theblade support section 6850 of the blade housing 6800 expandsproportionately with the outer diameter of the blade housing 6800 as thediameter changes from BHD1 to BHD2, thus, the diameter of the bearingregion 6860 of the blade support section 6850 of the blade housing 6800expands sufficiently to allow removal of the annular rotary knife blade6300 from the blade support section 6850 of the blade housing 6800.Stated another way, since the diameter of the bearing region 6860 of theblade support region 6850 of the blade housing 6800 is directlyproportional to the outer diameters BHD1, BHD2 of the blade supportsection 6850, the blade housing outer diameters BHD1, BHD2 may be usedas a convenient surrogate for the respective first, unexpanded diameterand second, expanded diameter of the blade housing bearing region 6860as the blade housing 6800 moves from the first, blade supportingposition 6898 to the second, open or expanded position 6899. Thus, forthe specific parameters of the bearing interface or structure 6550between the respective diameters of blade and blade housing bearingregions 6320, 6860, the second blade housing diameter BHD2 is sized tobe a magnitude that is sufficiently large such that the annular rotaryknife blade 6300 drops downwardly out of or is easily removed from theblade housing blade support section 6850 when the blade housing 6800 hasbeen moved to the second, blade changing position 6899.

Advantageously, the cam mechanism 6900 functions both to: a) secure theassembled blade-blade housing combination 6500 to the frame body 6250;and b) as desired, allows an operator or maintenance person toselectively change the diameter of the blade support section 6850 of theblade housing 6800 between the first, unexpanded blade housing diameterBHD1 (for purposes of supporting the rotary knife blade 6300 forrotation about the central axis of rotation during use of the poweroperated rotary knife 6000) and the second, expanded blade housingdiameter BHD2 (for purposes of removing the rotary knife blade 6300 fromthe blade housing 6800 for purposes of sharpening, blade changing,cleaning and/or maintenance of the power operated rotary knife 6000).That is, in the first, closed position 6998 of the cam mechanism 6900,the cam mechanism 6900 holds or secures the split blade housing 6800 inthe first, blade supporting position 6898 wherein the annular rotaryknife blade 6300 is supported for rotation about its central axis ofrotation R, and, in the second closed position 6999 of the cam mechanism6900, the cam mechanism 6900 secures the split ring blade housing 6800in the second, blade changing position 6899 wherein the diameter of theblade support section 6850 is increased from BHD1 to BHD2 to allow forremoval of the annular rotary knife blade 6300 from the split ring bladehousing 6800 to allow for sharpening or replacement of the rotary knifeblade 6300 and/or cleaning of the components of the head assembly 6200of the power operated rotary knife 6000. The blade housing diameter inthe first, blade supporting position 6898 is blade housing diameter BHD1corresponding to the first, closed position 6998 of the cam mechanism6900, is blade housing diameter BHD1 and the blade housing innerdiameter in the second, blade changing position 6899, corresponding tothe second, open position 6998 of the cam mechanism 6900, is bladehousing diameter BHD2.

As can best be seen in FIGS. 8-11, the split blade housing 6800comprises a split ring 6801 and includes a radial split 6801 a extendingthrough a diameter of the blade housing 6800 in the region of the bladehousing mounting section 6802 to allow for expansion of a circumferenceof the annular blade support section 6850 for purposes of removing theannular rotary knife blade 6300 from the annular blade support section6850 and inserting a new or resharpened annular rotary knife blade 6300into the annular blade support section 6850. With respect to themounting section 6802, the radially extending split 6801 a bisects aplanar central region 6811 of the mounting section 6802 defining a firstbody section or portion 6820 on one side of the split 6801 a and asecond body section or portion 6830 on an opposite side of the split6801 a. Advantageously, as can best be seen in FIGS. 2, 4, 21-24, thecam mechanism 6900 is mounted to the central region 6811 of the mountingsection 6802 and bridges the first and second body portions 6820, 6830.The radially extending split 6801 a defines a radially extending splitaxis BHSA of the blade housing mounting section 6802. The blade housingsplit axis BHSA is substantially orthogonal to and intersects a centerline or central axis CBH of the blade housing 6800. The blade housingcenter line CBH is substantially coincident with the central axis ofrotation R of the rotary knife blade 6300.

As best seen in FIGS. 10, 11 and 25, the blade housing split 6801 aextends through both the annular blade support section 6850 and themounting section 6802 extending from the blade support section 6850. Inreality, the blade housing split axis BHSA is a plane (as opposed to aline) that extends between opposing faces 6825, 6835 of the first andsecond body portions 6820, 6830 of the blade housing mounting section6802. However, for sake of simplicity, the blade housing split planewill be referred to the blade housing split axis BHSA. The cam mechanism6900 of the blade housing assembly 6700 includes a cam member 6910rotatably supported by a cam plate 6950. The cam member 6910 rotatesabout an axis of rotation CMA that is offset from, but substantiallyparallel to the central axis of rotation R of the rotary knife blade6300. The cam member axis of rotation CMA is substantially orthogonal toand intersects the longitudinal axis LA of the handle assembly 6110 andis substantially orthogonal to and intersects the split axis BHSAdefined by the blade housing split 6801 a. Changing or rotating the cammechanism 6900 from the first, closed position 6998 (corresponding tothe blade supporting position 6898 of the blade housing 6800) to thesecond, open position 6999 (corresponding to the blade changing position6899 of the blade housing 6800) increases a width of the split 6801 a,that is, the split width or split distance of a gap between opposingfaces 6825, 6835 of the first and second body portions 6820, 6840. Inthe first closed position 6998 of the cam mechanism 6900 (correspondingto the first, blade supporting position 6898 of the blade housing 6800),the gap or split distance between the opposing faces 6825, 6835 is afirst blade housing split width or split distance D1 and in the secondopen position 6999 of the cam mechanism 6900 (corresponding to thesecond, blade changing position 6899 of the blade housing 6800), the gapor split distance between the opposing faces 6830, 6850 is a secondblade housing split width or split distance D2.

The blade housing split distances D1, D2 are measured orthogonally to aradial direction of the split 6801 a, that is, orthogonally to the bladehousing split axis BHSA and parallel to a cutting plane CP of the rotaryknife blade 6300 at an inner wall 6852 of the blade support section 6850of the blade housing 6800. The blade housing split distances D1, D2 fora particular blade housing, of course, will vary depending on thespecific characteristics of the cam mechanism 6900 and the position andlength of the corresponding cam slots 6827, 6837 of the blade housingmounting section 6802. Specifically, as can be seen in FIGS. 10-11, 22and 24, the blade housing split distances D1, D2 are measured betweencircumferentially spaced apart ends 6852 a, 6852 b of the inner wall6852 of the blade support section 6850 of the blade housing 6800adjacent the split 6801 a. In one exemplary embodiment, the bladehousing split distance D1 corresponding to the first, blade supportingposition 6898 of the blade housing 6800 is approximately 0.06 in., whilethe blade housing split distance D2 corresponding to the second, bladechanging position 6899 of the blade housing 6800 is approximately 0.36in. In one exemplary embodiment, the blade housing outer diameter BHD1corresponding to the first, blade supporting position 6898 of the bladehousing 6800 is approximately 1.85 in., while the blade housing outerdiameter BHD2 corresponding to the second, blade changing position 6899of the blade housing is approximately 1.95 in. It being understood, ofcourse, that the dimensions of the split blade housing 6800 and the cammechanism 6900 and the required blade housing split distances D1, D2 andblade housing diameters BHD1, BHD2 will necessarily change based on anumber of parameters of the power operated rotary knife including: a)the diameter or size of the rotary knife blade to be supported by theblade housing; b) the dimensions and configuration of the blade-bladehousing bearing structure; and c) the specific style, configuration,dimensions, characteristics and parameters of the rotary knife bladeand/or the blade housing and/or other components of the power operatedrotary knife 6000. The dimensions set forth herein are merelyillustratory or representative of one exemplary embodiment of theblade-blade housing combination 6500 and the power operated rotary knife6000.

As can best be seen in FIG. 7, due to the fact that the assembledblade-blade housing combination 6500 includes the double axialblade-blade housing bearing structure 6550 having two axially spacedapart bearing structures, namely, a first blade-blade housing bearingstructure 6560, and a second blade-blade housing bearing structure 6570,the extent of radial overlap between the blade bearing region 6320 andthe blade housing bearing region 6860 is defined by an overlap of aportion of an outer wall 6318 of the body of annular rotary knife blade6300 and a portion of the inner wall 6852 of the blade support section6850 of the blade housing 6800. Advantageously, the cam mechanism 6900is designed to provide for sufficient difference or delta between theblade housing split distances D1, D2 and between the blade housingdiameters BHD1, BHD2 to allow for removal of the rotary knife blade 6300from the blade housing 6800 when the cam mechanism 6900 is in thesecond, open position 6999. The cam mechanism 6900 advantageouslyprovides for: a) a simple, durable and repeatable mechanical assemblyallowing an operator or maintenance person to increase in the diameterof the blade support section 6850 to a predetermined, desired bladehousing diameter BHD2 corresponding to the blade housing blade changingconfiguration 6899 that is sufficiently large for blade removalpurposes; and, b) equally important, a simple, durable and repeatablemechanical assembly allowing the operator or maintenance person toreturn in the diameter of the blade support section 6850 back to apredetermined, desired blade housing diameter BHD1 corresponding to theblade housing blade support configuration 6898 having a proper, desiredoperating or running clearance for the rotary knife blade 6300, withoutthe need for further operator or maintenance person adjustment of theblade housing diameter. That is, after the cam mechanism 6900 isactuated to move or rotate the cam member 6950 of the cam mechanism 6900to the first, closed position 6999, the power operated rotary knife 6000is ready for use by the operator without further adjustment to the bladehousing 6880 to change the operating or running clearance. The cammechanism 6900 of the blade housing assembly 6700 is advantageouscompared to the conventional technique of blade removal in a poweroperated rotary knife taught, for example, in U.S. Pat. No. 6,978,548 toWhited et al. The '548 patent discloses a blade housing structureincluding an expansion slot formed in the outer periphery of the bladehousing. Upon loosening one of the two clamping fasteners securing theassembled blade-blade housing combination to a frame body of the headassembly, a screwdriver may be inserted into the blade housing expansionslot and levered against the frame body to expand the blade housingdiameter and thereby remove the rotary knife blade from the bladehousing. The cam mechanism 6900 of the present disclosure eliminates theneed for such an expansion slot and prying with a screwdriver,providing, instead, a more secure and consistent mechanism for bladehousing expansion that provides for a reproducible and consistentexpansion of the blade housing diameter between the first bladesupporting position 6898 and the second blade changing position 6899wherein the blade housing split distance D2 in the second blade changingposition 6899 is sufficient to easily remove the rotary knife blade 6300from the blade housing 6800.

Additionally, the assembled blade-blade housing combination 6500includes the blade-blade housing bearing structure 6550 which has all ofthe advantages of extended useful life with respect to bearing andcomponent wear, as described with respect to the blade-blade housingbearing structure 2550 of the assembled blade-blade housing combination2500 of the power operated rotary knife 2000 of the third exemplaryembodiment of the '207 application. Accordingly and advantageously, whena sharpened, cleaned or new annular rotary knife blade 6300 is installedin the blade housing 6800 and the cam mechanism 6900 is moved to itsfirst closed position 6998, the diameter of the blade support section6850 of the blade housing 6800 is set to a predetermined, consistent,desired diameter. Thus, because the diameter of the blade supportsection 6850 is set at a predetermined, desired diameter, a desiredoperating or running clearance between the blade 6300 and the bladehousing 6800 in their respective bearing regions 6320, 6860 iscorrespondingly set and maintained by the cam mechanism 6900. Because ofthe advantageous wear characteristics of the respective bearing regions6320, 6860 of the rotary knife blade 6300 and blade housing 6800 due tothe two axially spaced apart bearing structures, namely, the a firstblade-blade housing bearing structure 6560 and the second blade-bladehousing bearing structure 6570, under proper cutting conditions and withproper maintenance, there may advantageously be no need for the operatorof the power operated rotary knife 6000 to make any adjustment to theblade housing diameter to account for changes in the operating clearanceof the assembled blade-blade housing combination 6500 during the courseof a work shift. That is, due to the improved wear characteristics ofthe bearing structure 6560 of the assembled blade-blade housingcombination 6500 of the power operated rotary knife 6000, the operatormay not have to make any adjustments to operating clearance during awork shift to account for increasing looseness of the rotary bladewithin the blade housing as the contacting bearing surfaces wear overtime during cutting or trimming operations. Such operator adjustment tothe blade housing diameter to compensate for perceived looseness of therotating blade within the blade housing (too much operating clearance)or perceived tightness of the rotating blade within the blade housing(too little operating clearance) are undesirable for a number ofreasons. First, the time required for adjustment of the operatingclearance is necessarily down time from cutting and trimming operations.Second, an inexperienced operator may perceive a need for adjustment andbounce between blade housing diameter positions where the operatingclearance is less than optimal with the blade running too loosely withinthe blade housing causing vibration and excessive component wear, toblade housing diameter position where operating clearance is more thanoptimal with the blade being too tightly held within the blade housingcausing excess heat generation and excessive component wear.

Thus, the cam mechanism 6900 of the present disclosure by advantageouslyproviding for a single predetermined, consistent, desired operating orrunning clearance when the cam mechanism 6900 is set to the first,closed position 6998 may provide for a full shift operation of the poweroperated rotary knife 6000 without requiring any need for the operatorto change the blade housing diameter from the preset blade housingdiameter BHD1 for operating clearance adjustment purposes. Additionally,the cam mechanism 6900 consistently sets the blade housing diameter tothe single, reproducible diameter, namely, the blade housing diameterBHD1, when the cam mechanism 6900 is in the first closed position 6999.Therefore, even if the annular rotary knife blade 6300 must be removedduring the course of a work shift for replacement, sharpening, orcleaning purposes, upon reassembly and movement of the cam mechanism6900 to the first, closed position 6998, blade housing diameter is resetthe predetermined, desired diameter and, thus, the operating clearancebetween the rotary knife blade 6300 and the blade housing 6800 isreturned to the predetermined, desired operating clearance. Undercertain conditions, the cam mechanism 6900, in conjunction with theextended wear capability of the double axial blade-blade housing bearingstructure 6550 of the assembled blade-blade housing combination 6500allows for a “set it and forget it” mode of operation of the poweroperated rotary knife 6000, allowing for greater operator efficiency andless operator downtime during a work shift by avoidance of operatoradjustments to operating clearance.

Because of the sliding blade-blade housing bearing interface 6550between the rotary knife blade 6300 and the split blade housing 6800 inthe assembled combination 6500 of the power operated rotary knife 6000,as would be recognized by one of skill in the art, running or operatingclearance between the rotary knife blade 6300 and the blade housing 6800must be provided to allow the rotary knife blade 6300 to rotaterelatively freely within the annular blade support section 6850 of thesplit blade housing 6800. Actual running clearance will depend on anumber of factors including the cutting or trimming application, theamount of time of use and the degree of wear of various components ofthe power operated rotary knife 6000 include the rotary knife blade 6300and the blade housing 6800, the extent and type of lubrication providedin the blade-blade housing bearing interface region. However, runningclearance typically is on the order of a 0.005-0.010 in. radialclearance or gap between the rotary knife blade 6300 and the bladehousing 6800.

Handle Assembly 6110

As best seen in FIGS. 1-6 and 8-9, the handle assembly 6110 is similarin structure and function to the handle assembly 110 of the poweroperated rotary knife 100 of the first exemplary embodiment, asdescribed in the '207 application. The handle assembly 6110 extendslongitudinally from the head assembly 6200 in the rearward direction RWalong the handle assembly central longitudinal axis LA. The handleassembly 6110 includes the central throughbore 6115 that extends fromand through a proximal end of the handle assembly 6110 to the distal end6112 of the handle assembly 6110. The throughbore 6115 is centered aboutthe central longitudinal axis LA of the handle assembly 6110. The handleassembly 6110 includes a central core 6152 that defines a portion of thethroughbore 6115. The central core 6152 supports an overlying hand piece6120 that defines a gripping surface for the operator of the poweroperated rotary knife 6000. A threaded outer surface 6162 of a forwardportion of the central core 6152 threads into a mating threaded proximalportion 6286 of an inner surface 6284 of a cylindrical annular boss 6280of the frame body 6250 to secure the handle assembly 6110 to the framebody 6250 of the head assembly 6250.

Frame Body 6250

As best seen in FIGS. 1-6 and 8-9, the frame body 6250 includes theforward or distal portion 6251, which supports the blade housingassembly 6700, and the rearward or proximal portion 6280, extending inthe rearward direction RW toward the handle assembly 6110. The rearwardportion 6280 of the frame body 6250 includes the cylindrical annularboss 6282. As noted above, the cylindrical annular boss 6282 includesthe inner surface 6284 having the threaded proximal portion 6286 whichreceives the threaded outer surface 6162 of the forward portion of thehandle assembly central core 6152 to secure the head assembly 6200 tothe handle assembly 6110. The rearward portion 6280 of the frame body6250 is similar in function and structure to the rearward portion 280 ofthe frame body 250 of the power operated rotary knife 100 of the firstexemplary embodiment, as described in the '207 application.

The frame body 6250 includes a throughbore 6290 which is generallyaligned with the central throughbore 6115 of the handle assembly 6110and extends along the handle assembly longitudinal axis LA. The rearwardportion 6280 includes the cylindrical annular boss 6282 having thethreaded proximal portion 6286 of an inner surface 6284 which receives athreaded outer surface 6162 of the central core 6152 of the handleassembly 6112. The forward portion 6251 of the frame body 6250 receivesand removably supports both a pinion gear shield 6297 and theblade-blade housing combination 6500, including the cam mechanism 6900which is part of the blade housing assembly 6700. The pinion gear shield6297 helps locate a drive gear assembly 6210 of a drive mechanism 6600(similar to the drive gear assembly 210 of the drive mechanism 600 ofthe first exemplary embodiment of the '207 application), including apinion gear 6610 and a sleeve bushing 6630. In this way, the frame body6250 releasably and operatively couples the drive gear assembly 6210 tothe assembled blade-blade housing combination 6500 such that the piniongear 6610 of the gear train 6604 of the drive gear assembly 6210operatively engages the driven gear 6340 of the annular rotary knifeblade 6300 to rotate the knife blade 6300 with respect to the bladehousing 6800 about the axis of rotation R.

The forward portion 6251 of the frame body 6250 includes a centralcylindrical region 6254, an upper surface 6260 and a planar lowersurface 6270. The planar lower surface 6270, best seen in FIG. 9,defines a planar mounting pedestal 6272 for affixing the assembledblade-blade housing combination 6500 to the frame body 6250. Thethroughbore 6290 of the frame body 6250 includes a forward cylindricalcavity 6290 a defined by the central cylindrical region 6254 of theforward portion 6251 of the frame body 6250 and a rearward cylindricalopening 6290 b defined by the cylindrical annular boss 6282 of therearward portion 6280. The forward wall 6252 of the forward portion 6251of the frame body 6250 defines an arcuate mounting surface 6252 a. Apair of threaded openings 6252 b positioned on opposite sides of theforward cylindrical cavity 6290 a of the throughbore 6290 extends intothe forward wall arcuate mounting surface 6252 a. A pair of threadedfasteners 6299 a pass through respective openings 6299 b in the piniongear shield 6297 to secure the pinion gear shield 6297 to the forwardwall 6252 of the frame body 6250.

The planar lower surface 6270 of the forward portion 6251 of the framebody 6250 is substantially parallel to and offset below the handleassembly longitudinal axis LA. The planar lower surface 6270 includes apair of threaded openings 6274, which are part of the planar mountingpedestal 6272 defined by the lower surface 6270. The threaded openings6274 which are orthogonal in direction to the general extent of theplanar lower surface 6270, receive a pair of threaded fasteners 6990.The fasteners 6990 include enlarged head portions 6991, unthreaded shaftportions 6992, and threaded end portions 6993. The threaded end portions6993 of the fasteners 6990 are received in the threaded openings 6274 ofthe planar lower surface 6270 to secure assembled blade-blade housingcombination 6500 to the frame body 6250. As the threaded fasteners 6990of the cam mechanism 6900 are tightened into the threaded openings 6274of the planar mounting pedestal 6272 of the frame body 6250, therespective heads 6991 of the threaded fasteners 6990 bear against thecam plate 6950 of the cam mechanism 6900, which, in turn, bears againsta planar lower surface 6810 a of the mounting section 6802 of the bladehousing 6800. Thus, tightening of the threaded fasteners 6990 sandwichesand affixes the mounting section 6802 of the blade housing 6800 to theframe body 6250. That is, as best seen in FIGS. 2 and 4-6, when thethreaded fasteners 6990 are tightened into the threaded openings 6274 ofthe planar mounting pedestal 6272, a planar upper surface 6808 a of theblade housing mounting section 6802 is in bearing contact with andsecured to the planar mounting pedestal 6272 of the lower surface 6270of the frame body 6250. The mounting plate 6950 of the cam mechanism6900, in turn, bears against the planar lower surface 6810 a of themounting section 6802 of the blade housing 6800 and is coupled to theplanar mounting pedestal 6272 of the lower surface 6270 of the framebody 6250. This securing of the blade housing assembly 6700 to the framebody 6250 also secures the assembled blade-blade housing combination6500, including the rotary knife blade 6300, to the frame body 6250 andproperly positions the rotary knife blade 6300 to be rotatably drivenabout the central axis of rotation R by the gear train 6604 of the drivemechanism 6600 of the power operated rotary knife 6000.

Advantageously, because the unthreaded shaft portion 6992 of the pair ofthreaded fasteners 6990 pass through generally oval shaped first andsecond mounting slots 6826, 6836 (FIGS. 10, 22, and 24) which are largerin extent than the respective diameters of the shaft portions 6992 ofthe threaded fasteners 6990, the blade housing 6800, even though securedto the frame body lower surface 6270, is sufficiently free to movecircumferentially such that the blade housing diameter is changedbetween the first blade housing diameter BHD1 when the cam mechanism6900 is in the first, closed position 6998 (corresponding to the first,blade supporting position 6898 of the blade housing 6800) and the secondblade housing diameter BHD2 when the cam mechanism 6900 is in thesecond, open position 6999 (corresponding to the second, blade changingposition 6898 of the blade housing 6800). Since the pair of threadedfasteners 6990 tread into the threaded openings 6274 of the planar lowersurface 6270 of the frame body 6250, the fasteners 6990 (and the cammechanism mounting plate 6950) are fixed with respect to the frame body6250 and thus are stationary with respect to the blade housing 6800.Under action of the cam member 6210 of the cam mechanism 6900 movingfrom the first, closed position 6998 (FIGS. 21 and 22) to the second,open position 6999 (FIGS. 23 and 24), the blade housing 6800 is movedcircumferentially from the first blade housing diameter BHD1 when thecam mechanism 6900 is in the first, closed position 6998 to the secondblade housing diameter BHD2 when the cam mechanism 6900 is in thesecond, open position 6999. The fact that the oval shaped first andsecond mounting slots 6826, 6836 are larger in extent than therespective diameters of the shaft portions 6992 of the threadedfasteners 6990 allows this circumferential movement of the blade housing6800 between the first blade housing diameter BHD1 and the second bladehousing diameter BHD2 while the blade housing 6800 remains secured tothe frame body 6250. Specifically, in the first, closed position 6998 ofthe cam mechanism 6900, the blade housing mounting slots 6826, 6836 arepositioned with respect to the pair of fasteners 6990 such that theunthreaded shaft portions 6992 of the pair of fasteners 6990 areadjacent respective first ends 6826 a, 6836 a of the blade housingmounting slots 6826, 6836, corresponding to the blade housing 6800 beingin the unexpanded blade housing diameter BHD1. By contrast, in thefirst, open position 6998 of the cam mechanism 6900, the blade housingmounting slots 6826, 6836 are positioned with respect to the pair offasteners 6990 such that the unthreaded shaft portions 6992 of the pairof fasteners 6990 are adjacent respective second ends 6826 b, 6836 b ofthe blade housing mounting slots 6826, 6836, corresponding to the bladehousing 6800 being in the expanded blade housing diameter BHD2.

As can best be seen in FIGS. 6 and 8-9, the frame body throughbore 6290receives and supports the drive gear assembly 6210 of the head assembly6200, which is part of the drive mechanism 6600 of the power operatedrotary knife 6000. Specifically, the drive gear assembly 6210 includesthe sleeve bushing 6630 which is received in the forward cylindricalcavity 6290 a of the central cylindrical region 6254 of the forwardportion 6251 of the frame body 6250. In turn, the pinion gear 6610 ofthe drive gear assembly 6210 is rotatably supported by the sleevebushing 6630 such that the pinion gear 6610, when driven by the drivefitting of the flexible shaft drive assembly (not shown, but similar tothe flexible shaft drive assembly 700 of the first exemplary embodimentof the '207 application) rotates about the pinion gear axis of rotationPGR, which is substantially coincident with the handle assemblylongitudinal axis LA. A gear head 6614 of the pinion gear 6610 isoperatively connected to the rotary knife blade driven gear 6340 suchthat a plurality of gear teeth 6615 of the gear head 6614 of the piniongear 6610 mesh with and rotationally drive a mating plurality of gearteeth 6341 of the driven gear 6340 of the rotary knife blade 6300 torotate the rotary knife blade 6300 about its central axis of rotation R.

Annular Rotary Knife Blade 6300

As can best be seen in FIGS. 6-9, the annular rotary knife blade 6300 isgenerally similar in structure and function to the annular rotary knifeblade 2300 of the power operated rotary knife 2000 of the thirdexemplary embodiment of the '207 application including the blade bearingregion 6320 of the annular blade body 6310 which is similar in structureand function to the blade bearing region 2320 of the annular blade body2310 of the rotary knife blade 2300 of the third exemplary embodiment ofthe '207 application.

The blade style of the rotary knife blade 6300 is referred to as astraight blade style. Generally, differences in blade style (e.g.,straight blade style, flat blade style, hook blade style and variationsand combinations thereof) relate to the structure of the respectivelower blade sections. While the exemplary rotary knife blade 6300 of thesixth exemplary embodiment is a straight blade style rotary knife blade,numerous other blade styles, including, but not limited to, hook andflat style blades and combinations of blade styles may be utilized, withan appropriate blade housing assembly 6700, in the power operated rotaryknife 6000 of the present disclosure, as would be understood by one ofskill in the art. It is the intent of the present disclosure to coverall such rotary knife blade styles and sizes and the corresponding bladehousings, that may be used in the power operated rotary knife 6000.

The annular rotary knife blade 6300 of the power operated rotary knife6000 includes the annular upper body or body section 6310 and the lowerblade section 6360 extending from the body 6310. The rotary knife blade6300 is supported for rotation about the central axis of rotation R bythe blade housing 6800 and a cutting edge 6361 of the blade section 6360defines the cutting plane CP (FIGS. 6 and 7) of the rotary knife blade6300. The cutting plane CP is substantially orthogonal to the centralaxis of rotation R.

The annular rotary knife blade 6300 includes an upper end or first end6302 and an axially spaced apart lower end or second end 6304, definingthe cutting edge 6361 of the blade 6300, and an inner wall 6306 and aradially spaced apart outer wall 6308. The blade section 6360 of therotary knife blade 6300 includes an upper end 6362, defined by adiscontinuity or knee 6362 a in an outer wall 6368 of the blade section6360, and a lower end 6364, which is coincident with the blade cuttingedge 6361, the cutting plane CP and the lower end 6304 of the rotaryknife blade 6300. The blade section 6360 also includes the inner wall6366 and the radially spaced apart outer wall 6368.

Turning to the annular body 6310 of the annular rotary knife blade 6300,the body 6310 includes the driven gear 6340, similar to the driven gear2340 of the rotary knife blade 2300 of the third exemplary embodiment ofthe '207 application, defining a driven gear region 6340 a of theannular and the bearing region 6320, similar to the bearing region 2320of the rotary knife blade 2300 of the third exemplary embodiment. Asbest seen in FIG. 7, the body 6310 includes an upper end 6312 and anaxially spaced apart lower end 6314 and an inner wall 6316 and aradially spaced apart outer wall 6318. The bearing region 6320 of theannular rotary knife blade 6300 includes a first bearing surface 6322and an axially spaced second bearing surface 6382. The first and secondbearing surfaces 6322, 6382 are both part of the outer wall 6318 of theannular rotary knife blade body 6310. The first bearing surface 6322 isdefined by an upper bearing bead 6311 of the body 6310 and at least aportion of the first bearing surface 6322 is defined by an outer surface6340 b of the driven gear 6340. The second bearing surface 6382 isdefined by a radially inwardly extending bearing race 6380.

Like the rotary knife blade 2300 and the annular blade housing 2400 ofthe assembled combination 2500 of the power operated rotary knife 2000of the third exemplary embodiment of the '207 application, the assembledcombination 6500 of the rotary knife blade 6300 and the annular bladehousing 6800 comprises the blade-blade housing bearing structure 6550that includes the first blade-blade housing bearing structure 6560 andthe second blade-blade housing bearing structure 6570. In the poweroperated rotary knife 2000 of the third exemplary embodiment, the firstblade-blade housing bearing structure 2560 included the first arcuatebearing surface 2322 of the bearing region 2320 of the rotary knifeblade 2300 engaging and bearing against the first arcuate bearingsurface 2462 of the bearing region 2460 of the blade support section2450 of the annular blade housing 2400. The first blade-blade housingbearing structure 6560 of the power operated rotary knife 6000 hassubstantially the same structure, namely, the first blade-blade housingbearing structure 6560 includes the first arcuate bearing surface 6322of the bearing region 6320 of the rotary knife blade 6300 which engagesand bears against a first arcuate bearing surface 6862, defined by abearing race 6866, of a bearing region 6860 of a blade support section6850 of the annular blade housing 6800. In the power operated rotaryknife 2000 of the third exemplary embodiment, the second blade-bladehousing bearing structure 2570 included the second bearing surface 2382of the bearing region 2320, defined by the bearing race 2380, of therotary knife blade 2300 engaging and bearing against the second bearingsurface 2482, defined by the bearing bead 2480, of the blade supportsection 2450 of the annular blade housing 2400. Similarly, the secondblade-blade housing bearing structure 6570 of the power operated rotaryknife 6000 has substantially the same structure, namely, a secondbearing surface 6382 of the bearing region 6320, defined by the bearingrace 6380, of the rotary knife blade 6300 engages and bears against asecond bearing surface 6882 of a bearing region 6880, defined by abearing bead 6880, of the blade support section 6850 of the annularblade housing 6800.

Blade Housing Assembly 6700

The blade housing assembly 6700 includes the annular split ring bladehousing 6800 (FIGS. 10, 11 and 25) and the cam mechanism 6900 (FIGS.12-15). As explained above, and as schematically depicted in FIGS.11-14, rotation of the cam member 6910 of the cam mechanism 6900 aboutits axis of rotation CMA from the first, closed position 6998 to thesecond, open position 6999 of the cam mechanism 6900 increases the widthof the split 6801 a from the first blade housing gap or split distanceD1 to the second blade housing split distance D2 between opposing faces6825, 6835 of the first and second body portions 6820, 6840 of the bladehousing mounting section 6802 and thereby moves the blade housing 6800from the first, blade supporting position 6898 of the blade housing 6800to the second, blade changing position 6899 of the blade housing 6800.Conversely, rotation of the cam member 6910 of the cam mechanism 6900about its axis of rotation CMA from the second, open position 6999 tothe first, closed position 6999 decreases the width of the split 6801 afrom the second blade housing gap or split distance D2 to the firstblade housing split distance D1 between opposing faces 6825, 6835 of thefirst and second body portions 6820, 6840 of the blade housing mountingsection 6802 and thereby moves the blade housing 6800 from the second,blade changing position 6899 of the blade housing 6800 to the first,blade supporting position 6898 of the blade housing 6800. As notedpreviously and as can be seen in FIGS. 10-11, 22 and 24, for purposes ofuniformity, the blade housing split distances D1, D2 are measuredbetween circumferentially spaced apart ends 6852 a, 6852 b of the innerwall 6852 of the blade support section 6850 of the blade housing 6800adjacent the split 6801 a.

Split Ring Blade Housing 6800

As best seen in FIGS. 7, 10, 11 and 25, the blade housing 6800 comprisesthe annular split ring 6801 including the split 6801 a that extendsradially through the annular blade support section 6850 and the mountingsection 6802, that is, extending radially through a blade housing outerwall 6800 b and a blade housing inner wall 6800 a. The annular bladesupport section 6850 supports the annular rotary knife blade 6300 forrotation about the blade central axis of rotation R. The mountingsection 6802 overlaps and extends radially outwardly from the bladesupport section 6850 and includes a generally planar mounting platform6803 which is secured to the frame body 6250 by being sandwiched betweenan upper surface 6952 of the cam plate 6950 of the cam mechanism 6900and the planar mounting pedestal 6272 defined by the lower surface 6370of the forward portion 6251 of the frame body 6250. Specifically, theplanar mounting platform 6803 is secured to the frame body 6250 by apair of threaded fasteners 6990 of the cam mechanism 6900. The pair ofthreaded fasteners 6990 extending through aligned openings 6982 a, 6982b of the cam plate 6950 and aligned slots 6826, 6836 of the bladehousing mounting section 6802 and thread into a pair of threadedopenings 6274 formed in the lower surface 6370 of the forward portion6251 of the frame body 6250. As the pair of threaded fasteners 6990 aretightened, the planar mounting platform 6803 is sandwiched between thecam plate 6950 of the cam mechanism 6900 and the planar mountingpedestal 6272 of the frame body 6250 and thereby secured to the framebody 6250.

The annular split blade housing 6800 includes the inner wall 6800 a andthe radially spaced apart outer wall 6800 b and an upper end 6800 c andan axially spaced apart lower end 6800 e. The upper end 6800 c of theblade housing 6800, which includes respective upper surfaces 6808 a,6856 a of both the radially extending mounting section 6802 and theannular blade support section 6850, defines a generally planar uppersurface 6808 a of the blade housing 6800. The lower end 6800 e of theblade housing 6800, which includes respective lower surfaces 6810 a,6858 a of both the mounting section 6802 and the blade support section6850, defines a generally planar lower surface 6800 f of the bladehousing 6800. The annular blade support section 6850 of the bladehousing 6800 is similar to the annular blade support section 2450 of theblade housing 2400 of the third exemplary embodiment and reference ismade to the description of the blade support section 2450 in the '207application for additional details of the structure and function of theblade support section 6850. The blade support section 6850 includes aninner wall 6852, which comprises and corresponds to the inner wall 6800a of the blade housing 6800, and a radially spaced apart outer wall6854, which defines a portion of the outer wall 6800 b of the bladehousing 6800, and the upper end 6856, which defines a portion of theupper end 6800 c of the blade housing 6800, and the axially spaced apartlower end, which defines a portion of the lower end 6800 e of the bladehousing 6800.

As can best be seen in FIG. 7, the inner wall 6852 of the blade supportsection 6850 defines the bearing region 6860 of the blade housing 6800,which is similar in structure and function to the bearing region 2460 ofthe blade support section 2450 of the blade housing 2400 of the thirdexemplary embodiment. The bearing region 6860 of the blade supportsection 6850 includes a bearing race 6866 comprising the arcuate firstbearing surface 6862 and a bearing bead 6880 comprising a second bearingsurface 6882 of the bearing region 6860. The bearing region 6860 of theblade housing 6800 engages a bearing region 6320 of the body 6310 of therotary knife blade 6300 to support the blade 6300 for rotation about thecentral axis of rotation R. The inner wall 6852 of the blade supportsection 6850 defines a blade housing central opening BHCO (FIGS. 9 and10) and is centered about and defines the blade housing center line CBH.The blade housing center line CBH, in the first, blade supportingposition 6898 of the blade housing 6800, is substantially coincidentwith the blade central axis of rotation R. A circumference defined bythe outer wall 6854 of the blade support section 6850 plus the splitwidth or split distance D1 defines the blade housing diameter BHD1 inthe first, blade supporting position 6898 of the blade housing 6800,while a circumference defined by the outer wall 6854 plus the splitwidth or split distance D2 defines the blade housing diameter BHD2 inthe second, blade changing position 6899 of the blade housing 6800. Inthe second, blade changing position 6899 of the blade housing 6800, theinner wall 6852 of the blade support section 6850 takes on a very slightoval or egg-shaped configuration because of the larger split width D2.

As can best be seen in FIGS. 10 and 11, the mounting section 6802 of theblade housing 6800 includes an inner wall 6804, which overlaps and iscoincident with the inner wall 6852 of the blade support section 6850and comprises and corresponds to a portion of the inner wall 6800 a ofthe blade housing 6800, and a radially spaced apart outer wall 6806,which defines a portion of the outer wall 6800 b of the blade housing6800, and an upper end 6808, which defines a portion of the upper end6800 c of the blade housing 6800, and an axially spaced apart lower end6810, which defines a portion of the lower end 6800 e of the bladehousing 6800. The upper end 6808 of the mounting section 6802 definesthe generally planar upper surface 6808 a. The upper end 6856 (definingthe upper planar surface 6856 a) of the blade support section 6850 andthe upper end 6808 (defining the upper planar surface 6808 a) of themounting section 6802 are advantageously coplanar with and together formthe planar upper surface 6800 d of the blade housing 6800. A firstarcuate recess 6815 is formed in the planar upper surface 6808 a of theupper end 6808 adjacent the inner wall 6800 a of the blade housing 6800.The first arcuate recess 6815 provides clearance for the gear head 6624of the pinion gear 6610 such that the pinion gear gear head 6624 ispositioned to engage the mating driven gear 6340 of the rotary knifeblade 6300. A second, shallower arcuate recess 6816 formed in the planarupper surface 6808 a of the upper end 6808 adjacent the inner wall 6800a of the blade housing 6800 is positioned radially outwardly from andaligned with the first arcuate recess 6815 and provides clearance forthe sleeve bushing 6630 that supports the pinion gear 6610 for rotationabout its pinion gear axis of rotation PGR. The first arcuate recess6815 circumferentially interrupts the arcuate first bearing surface 6862of the bearing region 6860 of the blade housing blade support section6850. The first and second arcuate recesses 6815, 6816, in turn, arebisected by the radially extending blade housing split 6801 a whichextends through the inner wall 6800 a of the blade housing 6800.

The lower end 6810 of the mounting section 6802 defines the generallyplanar lower surface 6810 a and the lower end 6858 (defining the lowerplanar surface 6858 a) are advantageously coplanar with and togetherform the planar lower surface 6800 f of the blade housing 6800. That is,as can best be seen in FIG. 55, the upper and lower surfaces 6800 d,6800 f define parallel planes providing the blade housing with a smoothprofile having substantially parallel upper and lower planar surfacesand uniform thickness in both the blade support section 6850 and themounting section 6802 of the blade housing 6800. That is, the planarmounting platform 6803 of the mounting section 6202 is substantially thesame thickness as the thickness of the blade support section 6850 asmeasured axially, that is, in a direction, substantially orthogonal tothe blade housing split axis BHSA and substantially parallel to theblade housing center line CBH.

Extending between circumferentially spaced apart first and second ends6812, 6814 of the mounting section 6802 is the central region 6811 ofthe mounting section 6802. The split 6801 a of the blade housing 6800divides or bisects the central region 6811 defining the first bodyportion 6820 and the second body portion 6830 separated along the bladehousing split axis BHSA by the split distance, which, as measured at theinner wall 6852 of the blade support section 6850, in the first, bladesupporting position 6898 of the blade housing 6800 is split distance D1and, in the second, blade changing position 6899 of the blade housing6800 is split distance D2. The first body portion 6820 of the bladehousing central region 6811 includes a generally planar upper surface6821, an axially spaced apart, generally planar lower surface 6822. Thefirst body portion 6820 also includes an inner surface 6823 forming partof: a) the inner wall 6800 a of the blade housing 6800; b) the innerwall 6804 of the mounting section 6802; and c) the coincident inner wall6852 of the blade support section 6850, and an outer surface 6824forming part of: a) the outer wall 6800 b of the blade housing 6800; andb) the outer wall 6806 of the mounting section 6802. The second bodyportion 6830 of the blade housing central region 6811 includes agenerally planar upper surface 6831, an axially spaced apart, generallyplanar lower surface 6832. The second body portion 6830 also includes aninner surface 6833 forming part of: a) the inner wall 6800 a of theblade housing 6800; b) the inner wall 6804 of the mounting section 6802;and c) the coincident inner wall 6852 of the blade support section 6850,and an outer surface 6834 forming part of: a) the outer wall 6800 b ofthe blade housing 6800; and b) the outer wall 6806 of the mountingsection 6802.

Opposing facing surfaces 6825, 6835 of the first and second bodyportions 6820, 6830 define the blade housing split 6801 a. The firstbody portion 6820 includes the generally oval shaped first mounting slot6826 extending between and through the upper and lower surfaces 6821,6822, while the second body portion 6830 includes the generally ovalsecond mounting slot 6836 extending between and through the upper andlower surfaces 6831, 6832. The unthreaded shaft portions 6992 of thepair of threaded fasteners 6990 of the cam mechanism 6900 pass throughthe respective mounting slots 6826, 6836 of first and second bodyportions 6820, 6830 of the central region 6811 of the mounting section6802 of the blade housing 6800. The unthreaded shaft portions 6992 ofpair of threaded fasteners 6990 are captured in respective cam plateopenings 6982 a, 6892 b of the cam plate 6950 and the enlarged heads6991 of the pair of fasteners 6990 bear against the cam plate 6950. Theunthreaded shaft portions 6992 of the pair of threaded fasteners 6990pass through the respective mounting slots 6826, 6836 of first andsecond body portions 6820, 6830 and the threaded end portions 6993 ofthe pair of fasteners 6990 then thread into respective threaded openings6274 of the planar mount pedestal 6272 of the lower surface 6270 of thefame body 6250 to secure the blade housing 6800 to the frame body 6250.An upper surface 6952 of the cam plate 6950 bears against the planarlower surface 6810 a of the blade housing mounting section 6802,specifically, the planar lower surfaces 6822, 6832 of the first andsecond body portions 6820, 6830 of the blade housing mounting section6802, to urge the planar upper surface 6808 a of the mounting section6802 against the planar mounting pedestal 6272 of the lower surface 6270of the fame body 6250 and secure the blade housing 6800 to the framebody 6250.

The lower surface 6822 of the first body portion 6820 includes a firstcam slot 6827 which receives and constrains a first cam pin 6930 of thecam member 6910 of the cam mechanism 6900. The first cam slot 6827includes a first end portion 6827 a and a second end portion 6827 b thatis closer to the split 6801 a. The first cam slot 6827 includes a linearportion 6828 defining a linear path of travel 6828 a for the first campin 6930 and an offset catch portion 6829. The first cam slot 6827 istransverse to the blade housing split axis BHSA and, if extended alongthe linear path of travel 6828 a, would intersect the blade housingsplit 6801 a. The lower surface 6832 of the second body portion 6830includes a second cam slot 6837 which receives and constrains a secondcam pin 6932 of the cam member 6910 of the cam mechanism 6900. Thesecond cam slot 6837 includes a first end portion 6837 a and a secondend portion 6837 b that is closer to the split 6801 a. The second camslot 6837 includes a linear portion 6838 defining a linear path oftravel 6838 a for the first cam pin 6930 and an offset catch portion6829. The second cam slot 6827 is transverse to the blade housing splitaxis BMA and, if extended along the linear path of travel 6838 a, wouldintersect the blade housing split 6801 a.

In the first, closed position 6998 of the cam mechanism 6900, the firstcam pin 6930 is positioned or located nearer the first end portion 6827a of the first cam slot 6827 and the second cam pin 6932 is positionedor located nearer the first end portion 6837 a of the second cam slot6837. In one exemplary embodiment, the first cam pin 6930 is positionedat the first end portion 6827 a of the first cam slot 6827 and thesecond cam pin 6932 is positioned at the first end portion 6837 a of thesecond cam slot 6837. Also, in the first, closed position 6998 of thecam mechanism 6900, the unthreaded shaft portions 6992 of the pair offasteners 6990 are positioned in proximity to or adjacent respectivefirst ends 6826 a, 6836 a of the blade housing mounting slots 6826,6836. As the cam member 6910 is rotated to the second, open position6999, the first and second cam pins 6930, 6932 move or translate withintheir respective first and second cam slots 6827, 6837 along therespective linear paths of travel 6928 a, 6938 a to positions orlocations nearer the respective second end portions 6827 b, 6837 b ofthe cam slots 6827, 6837, coming to rest in the respective offset catchportions 6829, 6839. This movement or translation of the first andsecond cam pins 6930, 6932 within their respective first and second camslots 6827, 6837 from the respective first end portions 6827 a, 6837 ato the respective second end portions 6827 b, 6837 b forces, by caromingaction, an expansion of the blade housing diameter from the unexpandedblade housing diameter BHD1, corresponding to the first, bladesupporting position 6898 of the blade housing 6800, to the expandedblade housing diameter BHD2, corresponding to the second, blade changingposition 6899 of the blade housing 6800, allowing for easy removal ofthe annular rotary knife blade 6300 from the blade housing blade supportsection 6850. Further, as the first and second body portions 6820, 6830of the blade housing mounting section 6802 move apart or spreadcircumferentially along the blade housing split 6801 a such that theblade housing diameter moves from the unexpanded blade housing diameterBHD1 to the expanded blade housing diameter BHD2, the unthreaded shaftportions 6992 of the pair of fasteners 6990 are now in proximity to oradjacent respective second ends 6826 b, 6836 b of the blade housingmounting slots 6826, 6836.

Conversely, as the cam member 6910 is rotated from the second, openposition 6999 to the first, closed position 6998, the first and secondcam pins 6930, 6932 move or translate within their respective first andsecond cam slots 6827, 6837 along the respective linear paths of travel6928 a, 6938 a to positions nearer the respective first end portions6827 a, 6837 a. This movement or translation of the first and second campins 6930, 6932 within their respective first and second cam slots 6827,6837 from the respective second end portions 6827 b, 6837 b to therespective first end portions 6827 a, 6837 a allows the blade housing6800, which is resiliently deformable and has the unexpanded bladehousing diameter BHD1 as its natural, undeformed condition, by carnrningaction, to return from the expanded blade housing diameter BHD2 to theunexpanded blade housing diameter BHD1. Further, as the blade housingmounting section 6802 moves circumferentially to return to itsunexpanded blade housing diameter BHD1, the unthreaded shaft portions6992 of the pair of fasteners 6990 are once again in proximity to oradjacent respective first ends 6826 a, 6836 a of the blade housingmounting slots 6826, 6836.

In one exemplary embodiment, the thickness or depth of the blade housing6800 is substantially uniform (ignoring the pinion gear and sleevebushing recesses 6815, 6816 and the first and second cam slots 6827,6837) along the entirety of the blade housing 6800 and is approximately0.21 in. In one exemplary embodiment, a length of each of the facingsurfaces of the first and second body portions 6820, 6830, as measuredalong the blade housing split axis BHSA, is approximately 0.63 in. Atotal width of the central region of the mounting section 6802, in theblade supporting position 6898 of the blade housing 6800, in oneexemplary embodiment, is approximately 1.59 in. In one exemplaryembodiment, the first and second oval mounting slots 6826, 6836 definean opening, as measured along the principal axis of the slots, ofapproximately 0.40 in. As can best be seen in FIG. 10, with respect tothe linear portions 6828, 6838 of the first and second cam slots 6827,6837, the linear portion 6828 of the first cam slot 6827, as measuredalong the linear path of travel 6828 a, is approximately 0.36 in., whilethe linear portion 6838 the second cam slot 6837, as measured along thelinear path of travel 6838 a, is approximately 0.32 in. As notedpreviously, it is understood, that these dimensions will necessarilychange based on the size and configuration, characteristics andparameters of the rotary knife blade to be supported by the bladehousing, the blade-blade housing bearing structure, and other parametersand characteristics of the power operated rotary knife 6000 andcomponents thereof.

Cam Mechanism 6900

As best seen in FIGS. 12-15, the cam mechanism 6900 includes the cammember 6910 supported for rotation about the cam member axis of rotationCMA by the cam plate 6950. The cam member 6910 rotates between thefirst, closed or locked position 6999 causing the blade housing 6800 tobe in the first, blade supporting position 6898 and the second, open orunlocked position 6999 causing the blade housing 6800 to be in thesecond, blade changing position 6899 having an increased diameter of theblade support section 6850 for the purpose of allowing the rotary knifeblade 6300 to be released from the blade housing 6800.

As best seen in FIGS. 19 and 20, the cam plate 6950 of the cam mechanism6900 is generally rectangular in plan view and includes an upper surface6952 and a spaced apart generally planar lower surface 6954. The upperand lower surfaces 6952, 6954 are spaced apart by a front side 6956,facing toward the annular rotary knife blade 6300, and a back side 6958,facing toward the handle assembly 6110. Extending between the front andback sides 6956, 6958 of the cam plate 6950 are first and second lateralsides 6960, 6962. The upper surface 6952 of the cam plate 6950 includesgenerally rectangular recess 6964 that receives and supports the cammember 6910. Positioned on either side of the recess 6964 are flankingportions 6980 of the cam plate 6950 that extend a full width or distancebetween the upper and lower surfaces 6952, 6954. The upper surfacerecess 6964 defines a seating region 6966 for the cam member 6910. Therecess 6964 extends through the front and back sides 6956, 6958 of thecam plate 6950. The recess 6964 is defined by a planar lower wall 6967and two side walls 6968 a, 6968 b that extend from the front side 6956to the back side 6958 of the cam plate 6950. The planar lower wall 6967of the recess 6964 is generally parallel to and intermediate between theupper and lower surfaces 6952, 6954 of the cam plate. A centrallylocated opening 6974 extends through lower surface 6954 of the cam plate6950 and intersects the recess 6964, passing though the planar lowerwall 6967 of the recess 6964. The central opening 6974 receives an uppercylindrical portion 6936 of a downwardly extending boss 6934 of the cammember 6910. A center line CLO through the central opening 6974 definesand is coincident with the cam member axis of rotation CMA. An innerwall 6976 defines the central opening 6974 and includes a radiallyinwardly extending rotation limitation tab 6978 of the central opening6974.

Advantageously, the rotation limitation tab 6978 is received in a cutout or arcuate notch 6938 in a side wall 6936 of the upper cylindricalportion 6935 of the downwardly extending boss 6934 of the cam member6910 to limit rotation of the cam member 6910 with respect to the camplate 6950. That is, because the tab 6978 of the cam plate 6950 extendsinto the arcuate notch 6938 of the cam member boss 6934, an arcuate orrotational path of travel RPOT of the cam member 6910 with respect tothe cam plate 6950 is necessarily limited by the arcuate orcircumferential extent of the arcuate notch 6938. When viewed in bottomplan view as shown, for example, in FIGS. 21-24, rotation of the cammember 6910 in the counterclockwise direction CCW (FIG. 21) (which wouldbe a clockwise direction if viewed in top plan view, e.g., FIG. 3) islimited by the abutment of the first end 6938 a of the arcuate notch6938 of the cam member 6910 and the protruding tab 6978 of the cam plate6950 (the tab 6978 schematically shown in dashed line in FIG. 22).Accordingly, in rotating the cam member 6910 from the second, openposition 6999 to the first, closed position 6998, the engagement of thetab 6978 and the first end 6938 a of the arcuate notch 6938 preventsover rotation of the cam member 6910. Rotation of the cam member 6910 inthe clockwise direction CW (FIG. 23) from the first, closed position6998 to the second, open position 6999 is limited by: a) the engagementof the first and second cam pins 6930, 6932 within the respective offsetcatch portions 6829, 6839 of the first and second cam slots 6827, 6837of the first and second body portions 6920, 6930 of the blade housingmounting section 6802; and b) the abutment of the first and secondfasteners 6990 of the cam mechanism 6900 with the second end portions6826 b, 6836 b of the blade housing mounting slots 6826, 6836. Duringassembly of the cam member 6910 to the cam plate 6910 or disassembly ofthe cam member 6910 from the cam plate 6910, the abutment of theopposite or second end of the notch 6938 of the cam member 6910 and theprotruding tab 6978 of the cam plate 6950 advantageously prevent overrotation of the cam member 6910 in the clockwise direction CW. Overrotation of the cam member 6910 with respect to the cam plate 6950 inthe clockwise direction CW during assembly could result in the cammember rectangular base 6912 pushing against and permanently bending ordeforming a pair of retainer springs 6972 a, 6972 b of the cam plate6950. In one exemplary embodiment, the rotational path of travel RPOT ofthe cam member 6930 in moving between the first, closed position 6998and the second, open position 6999 is approximately 45°.

The side walls 6968 a, 6968 b of the recess 6964 in the upper surface6952 of the cam plate 6950 includes respective outwardly bowed portions6970 a, 6970 b, that is, outwardly bowed with respect to the center lineCLO through the central opening 6974. Respective first and secondretainer springs 6972 a, 6972 b spaced from and extending substantiallyparallel to the planar lower wall 6967 of the upper surface recess 6964bridge the pair of outwardly bowed portions 6970 a, 6970 b of the sidewalls 6968 a, 6968 b. As can best be seen in FIGS. 13 and 15, the pairof retainer springs 6972 a, 6972 b bear against respective ledges 6922a, 6922 b formed in recessed regions 6920 a, 6920 b of the side wall6928 of a rectangular base 6912 of the cam member 6910 to maintain thecam member 6910 within the recess 6964 as the cam member 6910 is rotatedbetween its first and second positions 6998, 6999. Additionally, in thefirst, closed or locked position 6998 of the cam member 6910, centralportions 6973 a, 6973 b of the pair of retainer springs 6972 a, 6972 bbear against respective planar or flat areas 6924 a, 6924 b (best seenin FIGS. 13 and 17) of the recessed regions 6920 a, 6920 b of the sidewall 6918 of the cam member base 6912, to reproducibly, consistently andprecisely set the rotational position of the cam member 6910 in thefirst, closed position 6998 of the cam member and thereby reproducibly,consistently and precisely set the blade housing diameter BHD1 and thesplit distance D1 between opposing faces 6825, 6835 of the first andsecond body portions 6820, 6830 of the blade housing mounting section6802 in the first, blade supporting position 6898 of the blade housing6800, as further explained below.

The retainer springs 6972 a, 6972 b are disposed in respectivehorizontal openings in the cam plate 6950. The cam plate 6950 is stakedto displace material over the horizontal openings to maintain theretainer springs 6972 a, 6972 b permanently in place. The flankingportions 6980 a, 6980 b of the cam plate 6950 includes respective onesof a pair of openings 6982 a, 6982 b. The pair of openings 6982 a, 6982b each receive a respective one of a pair of threaded fasteners 6990.Each of the pair of threaded fasteners 6990 have a shank terminating ina threaded distal end portion. The respective shanks of the pair ofthreaded fasteners 6990 each include differing diameter portions betweenthe threaded distal portions and a hexagonal head of the fasteners 6990such that the fasteners 6990 are captured in and do not fall out oftheir respective openings 6982 a, 6982 b. The pair of fasteners 6990function to secure the blade housing assembly 6700, including the bladehousing 6800 and the cam mechanism 6800 to the frame body 6250 of thehead assembly 6200. Specifically, the threaded fasteners 6990 passthrough the respective cam plate openings 6982 a, 6982 b and also passthrough respective mounting slots 6826, 6836 of first and second bodyportions 6820, 6830 of the central region 6811 of the mounting section6802 of the blade housing 6800 and then thread into respective threadedopenings 6274 of the planar mount pedestal 6272 of the lower surface6270 of the frame body 6250. Thus, the blade housing 6800 is therebysecured to the frame body 6250 by having the blade housing mountingsection 6802 being sandwiched between the cam plate 6950 of the cammechanism 6900 and the planar mounting pedestal 6272 of the lowersurface 6270 of the frame body 6250 as the fasteners 6990 are threadedinto the threaded openings 6274 of the planar mount pedestal 6272 of thelower surface 6270 of the fame body 6250.

Because the mounting slots 6826, 6836 of the mounting section 6802 ofthe blade housing 6800 are oval shaped in top plan view, the mountingslots 6826, 6836 are longer, as viewed along the length of therespective slots 6826, 6836, than a diameter of the shanks of thethreaded fasteners 6990 of the cam mechanism 6900. Advantageously, asthe blade housing 6800 is moved by the cam mechanism 6900, the diameterof the blade support section 6850 between the first blade supportingposition 6898, having a smaller diameter of the blade support section6850, and the second blade changing position 6899, having a largerdiameter of the blade support section 6850, the blade housing 6800remains secured to the frame body 6250 by the sandwiching or bearingaction of the cam plate 6950 bridging and bearing against the bladehousing mounting section 6802 and urging the blade housing mountingsection against the planar mounting pedestal 6272 of the frame body6250. Stated another way, because the mounting slots 6826, 6836 of theblade housing mounting section 6802 are longer in extent than thediameter of the shanks of the threaded fasteners 6990, rotation of thecam member 6910 of the cam mechanism 6900 about its axis of rotation CMAfrom the first, closed position 6998 to the second, open position 6999of the cam mechanism 6900 increases the width of the split 6801 a fromthe first blade housing gap or split distance D1 to the second bladehousing split distance D2 between opposing faces 6825, 6835 of the firstand second body portions 6820, 6830 of the blade housing mountingsection 6802 and thereby moves the blade housing 6800 from the first,blade supporting position 6898 to the second, blade changing position6899 of the blade housing 6800, while the blade housing 6800 remainssecured to the frame body 6250. Conversely, because the mounting slots6826, 6836 of the blade housing mounting section 6802 are longer inextent or length than the diameter of the shanks of the threadedfasteners 6990, rotation of the cam member 6910 of the cam mechanism6900 about its axis of rotation CMA from the second, open position 6999to the first, closed position 6998 of the cam mechanism 6900 decreasesthe width of the split 6801 a from the second blade housing gap or splitdistance D2 to the first blade housing split distance D1 betweenopposing faces 6825, 6835 of the first and second body portions 6820,6830 of the blade housing mounting section 6802 and thereby moves theblade housing 6800 from the second, blade changing position 6896 to thefirst, blade supporting position 6898 of the blade housing 6800, again,while the blade housing 6800 remains secured to the frame body 6250.

As can best be seen in FIGS. 16-18 and 20-24, the cam member 6910includes the rectangular base 6912 having a generally planar uppersurface 6914 and a generally planar lower surface 6916 separated by thecircumferentially extending side wall 6918. A pair of opposite,diagonally spaced apart portions 6919 a, 6919 b of the side wall 6918include the recessed regions 6920 a, 6920 b. The recessed regions 6920a, 6920 b define respective ledges 6922 a, 6922 b which, as explainedpreviously, receive and bear against the pair of retainer springs 6972a, 6972 b of the cam plate 6950 to maintain the cam member 6910 withinthe recess 6964 of the cam plate 6950 as the cam member 6910 is rotatedbetween its first and second positions 6998, 6999. The recessed regions6920 a, 6920 b of the side wall 6918 of the cam member base 6912 alsoinclude respective planar or flat areas 6924 a, 6924 b. The planar orflat areas 6924 a, 6924 b of the side wall 6918 are spaced 180° apart asviewed in bottom plan view (FIG. 17), are substantially parallel andequidistant from the cam member axis of rotation CMA, and are locatednear respective end portions of the recessed regions 6920 a, 6920 b.Advantageously, in the first, closed position 6998 of blade housing6800, the planar or flat areas 6924 a, 6925 b bear against respectiveones of the pair of retainer springs 6972 a, 6972 b of the cam plate6950 set in the outwardly bowed portions 6970 a, 6970 b of the sidewalls 6968 a, 6968 b of the recess 6964 in the upper surface 6952 of thecam plate 6950. When the cam member 6910 is rotated about the cam memberaxis of rotation CMA when the cam member 6910 is rotated to the first,closed position 6999, the bearing of the flat areas 6924 a, 6924 b ofthe side wall 6918 of the cam member 6910 against the retainer springs6972 a, 6972 b causing the cam member 6910 to be set at a specificprecise and repeatable rotational orientation, shown schematically, forexample, in FIG. 13, with respect to the cam plate 6950 and the bladehousing mounting section 6802. As explained below, the bearing of theflat areas 6924 a, 6924 b of the side wall 6918 of the cam member 6910against the retainer springs 6972 a, 6972 b when the cam member 6910 isrotated to the first, closed position 6998 advantageously results in: a)a predetermined, consistent, reproducible and desired split distancevalue between opposing faces 6825, 6835 of the first and second bodyportions 6820, 6830 of the blade housing mounting section 6802, namely,split distance D1; and b) a predetermined, consistent, reproducible anddesired blade housing diameter, namely, blade housing diameter BHD1corresponding to the blade housing blade support configuration 6898having a proper, desired operating or running clearance for the rotaryknife blade 6300.

Extending axially from the lower surface 6916 of the cam member 6910 isthe downwardly projecting boss 6934. The boss 6934 passes through thecentral opening 6974 of the cam plate 6950 and extends beyond the lowersurface 6916 of the rectangular base 6912 of the cam member 6910. Theboss 6934 includes the generally upper cylindrical portion 6935 that isreceived in the cam plate central opening 6974 and a lower or distalportion 6940 which defines an accessible cam actuator 6943 which allowsthe cam plate 6910 to be rotated between its first and second positions6998, 6999. The lower portion 6940 of the boss 6934 extends below thelower surface 6916 and, in one exemplary embodiment, is formed into ahex shaped body 6942. The hex shaped body 6942 is accessible below thecam plate 6950 and functions as the cam actuator 6943. The cam actuator6943 may be rotated by a conventional ratchet socket or end wrench tomove or rotate the cam member 6910 between its first, closed position6998 and its second, closed position 6999. The cam actuator 6943 rotatesabout the cam member axis of rotation CMA and the boss 6934 is centeredabout the center line CLO through the central opening 6974 of the camplate 6950. The side wall 6936 of the upper cylindrical portion 6935 ofthe boss 6934 includes the arcuate notch 6938. Viewed in bottom planview, for example, as seen in FIGS. 21-24, rotation of the cam member6910 in the counterclockwise direction CCW is limited, as explainedpreviously, to the rotational path of travel RPOT by the interfit of thetab 6978 of the cam plate 6950 into the arcuate notch 6938 of the cammember boss 6934. In one exemplary embodiment, the upper surface 6914 ofthe cam member 6910 includes a slot 6944 to aid in the assembly of thecam mechanism 6900. Specifically, the slot 6944 allows for easy rotationof the cam member 6910 during assembly such that the cam member 6910 isappropriately seated in the seating region 6966 of the recess 6964 ofthe cam plate 6950 and the retainer springs 6972 a, 6972 b of the camplate 6950 properly bear against the ledges 6922 a, 6922 b of the cammember 6910 to maintain the cam plate 6910 in place with respect to thecam plate recess 6964.

Extending axially from the planar upper surface 6914 of the rectangularbase 6912 of the cam member 6910 are the pair of diagonally spaced apartfirst and second cam pins 6930, 6932. The first cam pin 6930 is locatedslightly inwardly of the cam member side wall 6918 near the recessregion 6920 a of the side wall 6918. The second cam pin 6932 is locatedslightly inwardly of the cam member side wall 6918 near the recessregion 6920 b of the side wall 6918. The first cam pin 6930 slidinglyengages and moves within the first cam slot 6827 formed in the lowersurface 6822 of the first body portion 6820 of the blade housingmounting section 6802. Specifically, the first cam pin 6930 isconstrained by the first cam slot 6827 to move along the generallylinear path of travel 6828 a defined by the linear portion 6828 of thefirst cam slot 6827. As noted previously, the first cam slot 6827, ifextended along the linear path of travel 6828 a, would intersect theblade housing split 6801 a. The first cam slot 6827 includes the firstend 6827 a and the second end 6827 b. The second end 6827 b of the camslot 6827 is closer to the blade housing split axis BHSA than the firstend 6827 a and includes the offset catch portion 6829. The first cam pin6930 slides along the first cam slot 6827 along the substantially linearpath of travel 6928 a as the cam member 6910 moves between its first andsecond positions 6998, 6999. Similarly, the second cam pin 6932slidingly engages and moves within the second cam slot 6837 formed inthe lower surface 6832 of the second body portion 6830 of the bladehousing mounting section 6802. Specifically, the second cam pin 6932 isconstrained by the first cam slot 6837 to move along the generallylinear path of travel 6838 a defined by the linear portion 6838 of thesecond cam slot 6837. As noted previously, the second cam slot 6837 istransverse to and, if extended along the linear path of travel 6838 a,would intersect the blade housing split 6801 a. The second cam slot 6837includes the first end 6827 a and the second end 6827 b. The second end6827 b of the cam slot 6827 is closer to the blade housing split axisBHSA than the first end 6827 a and includes the offset catch portion6829. The second cam pin 6932 slides along the second cam slot 6837along the substantially linear path of travel 6938 a as the cam member6910 moves between its first and second positions 6998, 6999.

In the first, closed position 6998 of the cam member 6910, the first campin 6930 is positioned at the first end 6827 a of the first cam slot6827 and the second cam pin 6932 is positioned at the first end 6837 aof the second cam slot 6837. As the cam actuator 6943 of the cam member6910 is rotated about the cam member axis of rotation CMA to move thecam plate from the first, closed position 6998 to the second, openposition 6999 for blade removal purposes, the first cam pin 6930 movesor slides along the path of travel 6828 a moving from the first end 6827a of the first cam slot 6827 to the second end 6827 b and is caught andheld in the offset catch portion 6829 of the first cam slot 6827.Simultaneously, as the cam actuator 6943 of the cam member 6910 isrotated about the cam member axis of rotation CMA to move the cam platefrom the first, closed position 6998 to the second, open position 6999for blade removal purposes, the second cam pin 6932 moves or slidesalong the path of travel 6838 a moving from the first end 6837 a of thesecond cam slot 6837 to the second end 6837 b and is caught and held inthe offset catch portion 6839 of the second cam slot 6837. Because therespective ends 6827 b, 6837 b are closer to the blade housing splitaxis BHSA, the movement of the first and second cam pins 6930, 6932along the respective paths of travel 6828 a, 6838 a of the first andsecond cam slots 6827, 6837 spreads or moves the opposing faces 6825,6835 of the first and second body portions 6820, 6830 of the bladehousing mounting section 6802 apart thereby increasing the diameter ofthe inner wall 6800 a of the blade housing 6800 and thereby increasingthe split distance from split distance D1 (blade supporting position6898) to split distance D2 (blade changing position 6899) allowing therotary knife blade 6300 to be removed from the blade housing bladesupport section 6850.

Since the blade housing 6800 is fabricated of a strong and resilientmaterial such as a hardenable grade of alloy steel or a hardenable gradeof stainless steel, when moved to an expanded diameter condition (i.e.,the blade changing position 6899), the natural tendency for the bladehousing 6800 to revert or spring back to its unexpanded or rest position(i.e., the blade supporting position 6898). Thus, the resiliency of theblade housing 6800 would tend to force the cam member 6910 to rotatefrom the second, open position 6999 back to the first, closed position6998. Advantageously, to mitigate this effect so that the operator doesnot have to continuously apply torque to the cam actuator 6943 of thecam member 6910 to maintain the blade housing 6800 in the second, bladechanging position 6899, in the second, open position 6999 of the cammember 6910, the cam pins 6930, 6932 are positioned in and stably restin the respect offset catch portion 6829, 6839 at the second ends 6827b, 6837 b of the respective cam slots 6827, 6837. Thus, once the bladehousing 6800 is in the second, blade changing position 6899, the bladehousing 6800 is stable and stays in its expanded diameter conditionwithout the application of continuous torque to the cam actuator 6943.

One of the advantages of the cam mechanism 6900 is that it provides asimple, durable and repeatable mechanical assembly which allow theoperator or maintenance person, by rotating the cam member 6910 to itsfirst, closed position 6998 to return in the diameter of the bladesupport section 6850 back to a predetermined, desired blade housingdiameter BHD1 corresponding to the blade housing blade supportconfiguration 6898 having a proper, desired operating or runningclearance for the rotary knife blade 6300, without the need for furtheroperator or maintenance person adjustment of the blade housing diameter.Stated another way, since the blade housing diameter and the splitdistance between opposing faces 6825, 6835 of the first and second bodyportions 6820, 6830 of the blade housing mounting section 6802 aredirectly proportional, setting the blade housing split distance at adesired value, e.g., the split distance D1, results in the blade supportsection 6850 of the blade housing 6800 having an outside diameter valuethat is desired, that is, the blade housing diameter BHD1.

At such time as the rotary knife blade 6300 is replaced and properlypositioned in the blade support section 6850 of the blade housing 6800,the operator applies torque to the cam actuator 6943 sufficient torotate the cam member 6910 from its second, open position 6999 to itsfirst, closed position 6998. Advantageously, in addition to the naturalresiliency of the blade housing 6800 which tends to cause the blade toreturn to its first, closed position 6998, the retainer springs 6972 a,6972 b of the cam plate 6950 aid in returning the blade housing 6800 tothe first, closed position 6998 and, more specifically, aid in returningthe blade housing 6800 to a position wherein: a) the split distancevalue is consistently and reproducibly the desired split distance D1;and b) the blade housing diameter value is consistently and reproduciblythe desired blade housing diameter BHD1. As can best be seen in FIG. 13,in one exemplary embodiment, in the first, closed position 6998 of bladehousing 6800, central portions 6973 a, 6973 b of the retainer springs6972 a, 6972 b bear against respective planar or flat areas 6924 a, 6924b of the recessed regions 6920 a, 6920 b of the side wall 6918 of thecam member 6910. When the cam member 6910 is rotated about the cammember axis of rotation CMA when the cam member 6910 is rotated to thefirst, closed position 6998, the bearing of central portions 6973 a,6973 b of the retainer springs 6972 a, 6972 b against the flat areas6924 a, 6924 b of the cam member 6910 cause the cam member 6910 to beset at a specific precise and repeatable rotational orientation, asdepicted schematically in FIG. 13, with respect to the cam plate 6950and the blade housing mounting section 6802. The circumferential extentof a region of contact between the central portion 6973 a of theretainer spring 6972 a and the flat area 6924 a of the cam member sidewall 6918 is large. Similarly, the circumferential extent of a region ofcontact between the central portion 6973 b of the retainer spring 6972 band the flat area 6924 b of the cam member side wall 6918 is also large.These large circumferential regions of contact advantageously functionto essentially firmly lock and maintain the rotational orientation ofthe cam member 6910 when the cam member is in the first, closed position6998. Because of the bearing contact between the central portions 6973a, 6973 b of the retainer springs 6972 a, 6972 b against the flat areas6924 a, 6924 b of the cam member 6910, in the first, closed position6998 of the cam member 6910, the retainer springs 6972 a, 6972 b areunder tension and, thus, are slightly bowed or deflected. However, thelimited deflection of the retainer springs 6972 a, 6972 b in the first,closed position 6998 of the cam member 6910 does not deform orpermanently bend the retainer springs 6972 a, 6972 b.

Since the cam member 6910 is always set at the specific predeterminedrotational orientation with respect to the cam plate 6950 and the bladehousing mounting section 6802, the position of the cam member pins 6930,6932 of the earn member 6910 are set a specific, predetermined andrepeatable locations within their respective cam slots 6827, 6837. Thatis, because of the bearing of the central portions 6973 a, 6973 b of theretainer springs 6972 a, 6972 b in the first, closed position 6998 ofthe blade housing 6800 against the flat areas 6924 a, 6924 b of the cammember 6910, the position or location of the cam member pin 6930 at thefirst end 6827 a of the cam slot 6827 of the first body portion 6920 ofthe blade housing mounting section or mounting portion 6802 and theposition of the cam member pin 6932 at the first end 6837 a of the camslot 6837 of the first body portion 6930 of the blade housing mountingportion 6802 is set precisely, consistently and reproducibly each timethe cam member 6910 is rotated to the first, closed position 6999. Theprecise and reproducible positioning of the cam member pins 6930, 6932within their respective cam slots 6927, 6937 resulting from theengagement of the cam plate retainer springs 6972 a, 6972 b against therespective planar or flat areas 6924 a, 6924 b of the recessed regions6920 a, 6920 b of the side wall 6918 of the cam member 6910 when theblade housing 6800 is in the first, blade supporting position 6898functions to move the mounting section 6802 of the blade housing 6800into the same position or configuration every time the cam member 6910is rotated to its first, closed position 6998.

The bearing of the central portions 6973 a, 6973 b of the cam plateretainer springs 6972 a, 6972 b against the respective planar or flatareas 6924 a, 6924 b of the recessed regions 6920 a, 6920 b of the sidewall 6918 of the cam member 6910 results in a consistent configurationof the mounting section 6802 of the blade housing 6800 and a consistentconfiguration of the blade support section 6850 of the blade housing6800 when the cam member 6910 is in the first, closed position 6898.That is, when the cam member 6920 is in the first, closed position 6998,a split distance value between opposing faces 6825, 6835 of the firstand second body portions 6820, 6830 of the blade housing mountingsection 6802 is precise, consistent, and reproducible, namely, thedesired split distance D1. The split distance D1 results in the bladesupport section 6850 of the blade housing 6800 having the desireddiameter value, namely, blade housing diameter BHD1. That is, every timethe cam member 6910 is rotated to its first, closed position 6998, thesplit distance value achieved is substantially identical to the desiredsplit distance value, namely, the split distance D1 and the bladehousing diameter achieved is substantially identical to the desiredblade housing diameter value, namely, blade housing diameter BHD1. Inthis condition and configuration of the blade housing 6800, the poweroperated rotary knife 6000 is ready for operation without the need forfurther adjustment of the blade housing diameter BHD1 by the operator.Additionally, as mentioned previously, depending upon cutting conditionsand maintenance of the power operated rotary knife 6000, the extendedwear capability of the double axial blade-blade housing bearingstructure 6550 of the assembled blade-blade housing combination 6500advantageously allows for a “set it and forget it” mode of operation ofthe power operated rotary knife 6000. That is, once a new or sharpenedrotary knife blade 6300 has been inserted into the blade housing bladesupport section 6850 of the blade housing 6800, as the cam member 6910is moved to the first, closed position 6998, the blade housing 6800concurrently moves to its first, blade supporting position 6898 whereinthe split distance between the opposing faces 6825, 6835 of the firstand second body portions 6820, 6830 of the blade housing mountingsection 6802 is consistently and reproducibly is set at thepredetermined, desired split distance value, namely, split distance D1and desired blade housing diameter BHD1. This precise, reproduciblepositioning and configuration of the blade housing 6800 in the first,blade supporting position 6898 provides for a desired value of operatingor running clearance between the annular rotary knife blade 6300 and theblade support section 6850 of the blade housing 6800. Given the extendedwear capability of the double axial blade-blade housing bearingstructure 6550 of the assembled blade-blade housing combination 6500 anddepending on cutting conditions, maintenance of the power operatedrotary knife 6000, along with other variables, there may be no need forthe operator to make adjustments to blade housing diameter to changeoperating or running clearance during a work shift thereby allowing forgreater operator efficiency and less operator downtime during the workshift, as explained previously.

In one exemplary embodiment, the rectangular base 6912 of the cam member6910 has length and width dimensions of approximately 0.47 in. and 0.78in. and a thickness of 0.10 in., while a center to center diagonaldistance between the first and second cam pins 6930, 6932 isapproximately 0.60 in. In one exemplary embodiment, a center to centerdistance between the first and second openings 6982 a, 6982 b of thefirst and second flanking portions 6980 a, 6880 b of the cam plate 6950is approximately 1.22 in., while the thickness or depth of the cam plate6950 in the first and second flanking portions 6980 a, 6880 b isapproximately 0.17 in. and a diameter of the central opening 6974 of thecam plate is approximately 0.37 in. Again, as noted previously, it isunderstood, that these dimensions will necessarily change based on thesize and configuration, characteristics and parameters of the rotaryknife blade to be supported by the blade housing, the blade-bladehousing bearing structure, and other parameters and characteristics ofthe power operated rotary knife 6000 and components thereof.

Seventh Embodiment—Power Operated Rotary Knife 7000

A seventh exemplary embodiment of a power operated rotary knife of thepresent disclosure is shown generally at 7000 in FIGS. 26-32. The poweroperated rotary knife 7000 extends between a distal or forward end 7001and a proximal or rearward end 7002 of the power operated rotary knife7000. The power operated rotary knife 7000 includes an elongated handleassembly 7110, a head assembly 7200, which is releasably secured to afront or distal end 7112 of the handle assembly 7110, and a drivemechanism 7600, including a gear train 7604. The handle assembly 7110includes a central throughbore 7115 that extends along a centrallongitudinal axis LA of the handle assembly 7110. The head assembly 7200extends from the handle assembly 7110 along the central longitudinalaxis LA in a forward or distal direction FW. The throughbore 7115 (FIG.30) of the handle assembly 7110 receives a distal portion of a flexibledrive shaft assembly (similar to the flexible drive shaft assembly 700of the first exemplary embodiment) which rotates the drive mechanism7600, as described in the first exemplary embodiment of the '207application. As used herein, the forward direction FW will be adirection extending generally along or parallel to the handle assemblylongitudinal axis toward the distal end 7001 of the power operatedrotary knife 7000 and a rearward direction RW will be a directionextending generally along or parallel to the handle assemblylongitudinal axis LA toward the proximal end 7002 of the power operatedrotary knife 7000.

As best seen in FIGS. 32 and 33, the head assembly 7200 includes a framebody 7250 including a forward portion 7251 and a rearward portion 7280.The rearward portion 7280 of the frame body 7250 includes an annularboss 7282 that defines a mounting structure that receives and engagesthe front end 7112 of the handle assembly 7110 to secure the headassembly 7200 to the handle assembly 7110. The head assembly 7200further includes an annular rotary knife blade 7300, substantiallysimilar to the annular rotary knife blade 6300 of the power operatedrotary knife 6000 of the sixth exemplary embodiment, as described above.The head assembly 7200 further includes a blade housing assembly 7700including a split ring blade housing or split blade housing 7800 whichsupports the annular rotary knife blade 7300 for rotation about acentral axis of rotation R and a cam assembly or cam mechanism 7900which is affixed to the split blade housing 7800. The blade housing 7800includes an annular blade support section 7850 which supports the rotaryknife blade 7300 for rotation and a mounting portion or mounting section7802, which may be considered as a tongue or projection extendingradially outwardly and in a generally rearward direction RW from theannular blade support section 7850. The annular blade support section7850 is centered about a blade housing center line or central axis CBH(schematically depicted in FIGS. 28-30), specifically, an inner wall7852 of the blade support section 7850, which defines a bearing region7860 of the blade housing 7800 for rotatably supporting the annularrotary knife blade 7300, is centered about the blade housing center lineCBH. The blade housing center line CBH is substantially parallel to thecentral axis of rotation R of the rotary knife blade 7300 and, in afirst, blade supporting position 7898 of the blade housing 7800, theblade housing center line CBH is substantially coincident with therotary knife blade central axis of rotation R.

As best seen in FIGS. 36 and 39, a split 7801 a extends through adiameter of the split ring blade housing 7800 in a region of the bladehousing mounting section 7802 to allow for expansion of a circumferenceof the annular blade support section 7850 for purposes of removing theannular rotary knife blade 7300 from the annular blade support section7850 and inserting a new or resharpened annular rotary knife blade 7300into the annular blade support section 7850. With respect to themounting section 7802, a split 7801 a extends through and divides acentral region 7811 of the mounting section 7802 defining a first bodysection or portion 7820 on one side of the split 7801 a and a secondbody section or portion 7830 on an opposite side of the split 7801 a. Inthe region of the mounting section 7802, an inner wall 7804 of themounting section 7802 overlaps and is coincident with an inner wall 7852of the blade support section 7850 of the split blade housing 7800.Unlike the radially extending split 6801 a of the mounting section 6802of the blade housing 6800 of the sixth embodiment which defines thesplit axis BHSA that intersects the blade housing center line CBH andbisects t mounting section 6802 into two substantially identically sizedbody portions 2820, 6830, the split 7801 a of the mounting section 7802of the blade housing 7800 of the seventh embodiment, when viewed in planview, is a generally dog-leg shaped split having a first, radiallyextending split portion 7801 b and a second, angled split portion 7801c, which extends from but is transverse to the first, radially extendingsplit portion 7801 b. Thus, when viewed in plan view, while the split7801 a bisects the mounting section 7802, the resulting first and secondbody portions 7820, 7830 are different in shape and size.

In a first, closed, locked or home position 7998 of the cam mechanism7900 (shown schematically in FIGS. 40 and 42), the cam mechanism 7900positions or secures the blade housing 7800 in the first, bladesupporting position 7898, characterized by a first, unexpanded or bladesupporting blade housing diameter BHD1 (depicted schematically in FIG.42), and, in a second, open, unlocked or expanded position 7999 of thecam mechanism 7900 (shown schematically in FIGS. 41 and 43), the cammechanism 7900 positions or secures the blade housing 7800 in a second,blade changing position 7899, characterized by a second, expanded bladehousing diameter BHD2 (FIG. 43). In the first, blade supporting position7898, as measured at the inner wall 7852 of the blade support section7850 adjacent the split 7801 a, there is a first width or split distanceD1 (FIG. 39) between opposing faces 7825, 7835 of the first body portion7820 and the second body portion 7830 of the central region 7811 of themounting section 7802. In the second, blade changing support position,as measured at the inner wall 7852 of the blade support section 7850,there is a second width or split distance D2 (FIG. 43) between opposingfaces 7825, 7835 of the first body portion 7820 and the second bodyportion 7830 of the central region 7811 of the mounting section 7802,the second split distance D2 being greater than the first split distanceD1.

As best seen in FIG. 31, the annular rotary knife blade 7300 includes anupper body portion or upper body 7310 and a lower blade section 7360extending from the body 7310. The annular rotary knife blade 7300 isrotatably driven by the drive mechanism 7600. The forward portion 7251of the frame body 7250 supports the drive mechanism 7600 and positions agear head 7614 of a pinion gear 7610 of the gear train 7604 of the drivemechanism 7600 to interface with a driven gear 7340 of the body 7310 ofthe rotary knife blade 7300 to thereby rotate the blade 7300 about itscentral axis of rotation R. As best seen in FIG. 31, an assembledblade-blade housing combination 7500, which is similar in structure andfunction to the assembled blade-blade housing combination 6500 of thepower operated rotary knife 6000 of the sixth exemplary embodiment,includes the annular rotary knife blade 7300 and the split blade housing7800 supporting the rotary knife blade 7300 for rotation about theannular rotary knife blade's central axis of rotation R. The assembledblade-blade housing combination 7500 includes a blade-blade housingbearing structure 7550, similar to the blade-blade housing bearingstructure 2550 of the assembled blade-blade housing combination 2500 ofthe third exemplary embodiment of the '207 application. Morespecifically, the blade-blade housing bearing structure 6550 includestwo axially spaced apart bearing structures, namely, a first or upperblade-blade housing bearing structure 7560 and a second or lowerblade-blade housing bearing structure 7570. As used herein, the upwarddirection UP and downward direction DW shall be parallel to the centralaxis of rotation R of the rotary knife blade 7300 and in the directionsshown, for example, in FIG. 29. Thus, the first blade-blade housingbearing structure 7560 is above or upward with respect to the second orlower blade-blade housing bearing structure 7570.

Various components and assemblies of the power operated rotary knife7000 are substantially similar in structure and/or function tocorresponding components and assemblies of the power operated rotaryknife 6000 of the sixth exemplary embodiment, as described above, andare substantially similar in structure and/or function to correspondingcomponents and assemblies of the power operated rotary knife 2000 of thethird exemplary embodiment of the '207 application. In the interest ofbrevity, components and assemblies of the power operated rotary knife7000 that are similar to the corresponding components and assemblies ofthe power operated rotary knife 6000 of the sixth exemplary embodimentin structure and/or function or that are similar to the correspondingcomponents and assemblies of the power operated rotary knife 2000 of thethird exemplary embodiment of the '207 application will not be fullydescribed herein. Instead, reference is made to the description of suchcomponents and assemblies set forth above in connection with the poweroperated rotary knife 6000 and/or the power operated rotary knife 2000,as set forth in the '207 application. Materials/fabrication ofcomponents and assemblies of the power operated rotary knife 6000 of thesixth exemplary embodiment, as described above, are similar tomaterials/fabrication of corresponding components and assemblies of thepower operated rotary knife 6000 and/or materials/fabrication ofcorresponding components and assemblies of the power operated rotaryknives 100, 1000, 2000, 3000 and the blade-blade housing combination4500, as described in the '207 application. Such descriptions ofcomponents and assemblies of the power operated rotary knife 6000 of thesixth exemplary embodiment, as described above, and the power operatedrotary knives 100, 1000, 2000, 3000 and the blade-blade housingcombination 4500 are hereby incorporated by reference from the '207application in the following description of the power operated rotaryknife 7000 of the seventh exemplary embodiment. Identification of axes,lines, planes and directions for the power operated rotary knife 7000,as set forth herein, will be the same as used for the description of thepower operated rotary knife 6000 of the sixth exemplary embodiment andthe power operated rotary knives 100, 1000, 2000, 3000 in the '207application.

Annular Rotary Knife Blade 7300

As best seen in FIGS. 31-33, the annular rotary knife blade 7300includes the upper body portion or upper body 7310 and the lower bladesection 7360 extending from the body 7310. The blade style of the rotaryknife blade 7300 is referred to as a hook blade style, contrasted withthe straight blade style of the annular rotary knife blade 6300 of thesixth embodiment. Generally, differences in blade style (e.g., straightblade style, flat blade style, hook blade style and variations andcombinations thereof) relate to the structure of the respective lowerblade sections. While the exemplary rotary knife blade 7300 of theseventh exemplary embodiment is a hook blade style rotary knife blade,numerous other blade styles, including, but not limited to, straight andflat style blades and combinations of blade styles may be utilized, withan appropriate blade housing assembly 7700, in the power operated rotaryknife 7000 of the present disclosure, as would be understood by one ofskill in the art. It is the intent of the present disclosure to coverall such rotary knife blade styles and sizes and the corresponding bladehousings, that may be used in the power operated rotary knife 7000.

The annular rotary knife blade 7300 is supported for rotation about thecentral axis of rotation R by the blade housing 7800 and the blade 7300is generally cylindrical and extends axially between an upper end 7302and a lower end 7304 and extends radially between an inner wall 7306 anda lower end 7308. The blade section 7360 includes a cutting edge 7361 atthe lower end 7304 of the blade 7300 which defines the cutting plane CP(FIG. 30) of the rotary knife blade 7300. The cutting plane CP issubstantially orthogonal to the central axis of rotation R. The bladesection 7360 of the rotary knife blade 7300 includes an upper end 7362,defined by a discontinuity or knee 7362 a in an outer wall 7368 of theblade section 7360, and a lower end 7364, which is coincident with theblade cutting edge 7361, the cutting plane CP and lower end 6304 of therotary knife blade 6300.

The annular body 7310 of the blade 7300 includes the driven gear 7340and the bearing region 7320, similar to the driven gear 6340 and bearingregion 6320 of the rotary knife blade 6300 of the sixth exemplaryembodiment. As best seen in FIG. 31, the body 7310 includes an upper end7312 and an axially spaced apart lower end 7314 and an inner wall 7316and a radially spaced apart outer wall 7318. The bearing region 7320 ofthe annular rotary knife blade 7300 includes a first bearing surface7322 and an axially spaced second bearing surface 7382. The first andsecond bearing surfaces 7322, 7382 are both part of the outer wall 7318of the annular rotary knife blade body 7310. The first bearing surface7322 is defined by an upper bearing bead 7311 of the body 7310 and atleast a portion of the first bearing surface 7322 is defined by an outersurface 7340 b of the driven gear 7340. The second bearing surface 7382is defined by a radially inwardly extending bearing race 7380.

Blade Housing Assembly 7700

The blade housing assembly 7700 of the head assembly 7200 of the poweroperated rotary knife 7000 of the seventh exemplary embodiment includesthe split ring blade housing 7800 and the cam mechanism 7900 whichfunctions to move the blade housing 7800 between the first, bladesupporting position 7898 to the second, blade changing position 7899, aspreviously described.

The blade housing assembly 7700, while similar in function to the bladehousing assembly 6700 of the head assembly 6200 of the power operatedrotary knife 6000 of the sixth exemplary embodiment includes a number ofstructural changes to a mounting section 7802 of the split blade housing7800 and the cam mechanism 7900 providing for various functional andoperating improvements, as compared to the blade housing assembly 6700of the power operated rotary knife 6000. Additionally, because bladehousing assembly 7700 is affixed to the planar mounting pedestal 7272 ofthe lower surface 7270 of the forward portion 7251 of the frame body7250, the frame body 7250 of the head assembly 7200 includes certainstructural changes as compared to the frame body 6250 of the headassembly 6250 of the power operated rotary knife 6000, as describedbelow, to accommodate certain structural features of the mountingsection 7802 of the split blade housing 7800.

Blade Housing 7800

The mounting section 7802 of the blade housing 7800 includes differencesin the position and extent of the split 7801 a, as compared to the split6801 a of the mounting section 6802 of the blade housing 6800 of thefirst exemplary embodiment. As discussed above, the radially extendingsplit 6801 a of the mounting section 6801 of the blade housing 6800 ofthe sixth exemplary embodiment which, when viewed in plan view,constituted a single split that extended substantially along a radialpath or radial line between the inner and outer walls 6804, 6806 of themounting section 6801, bisecting the first and second body portions6820, 6830 of the blade housing mounting section 6802 and wherein theblade housing split axis BHSA of the split 6801 intersected the bladehousing center line CBH. However, as best seen in FIG. 39, the split7801 a of the mounting section 7801 of the blade housing 7800 of thesixth exemplary embodiment includes the two, intersecting, non-parallelsplit portions 7801 b, 7801 c that essentially form, when viewed in planview, a dog-leg shaped split. The split 7801 a includes the first,rearward radially extending split portion 7801 b, extending along afirst blade split axis BHSA1, and the second, forward extending angledsplit portion 7801 c, extending along a second angled split axis BHSA2.The first split portion 7801 b extends along the first blade housingsplit axis BHSA1, which can be viewed as a radius line extendingorthogonally from the blade housing center line CBH. The first bladehousing split axis BHSA1 extends along and is centered between opposingfaces 7825, 7835 of the first and second body portions 7820, 7830 of theblade housing mounting section 7802. The first blade housing split axisBHSA1 intersects and is orthogonal to the blade housing center line CBH.The first radial split axis BHSA1 of the first split portion 7801 bintersects the inner wall 7852 of the blade support section 7850 at anintersection position or location 7801 i. As mentioned with respect tothe split 6801 a of the blade housing mounting section 6802 of the bladehousing 6800 of the sixth exemplary embodiment, the first blade housingsplit axis BHSA1 and the second blade housing split axis BHSA2 are, inreality, planes (as opposed to axis lines) that extends between opposingfaces 7825, 7835 of the first and second body portions 7820, 7830 of theblade housing mounting section 7802. That is, the first split portion7801 b may be considered as extending along a vertically extending,longitudinal plane BHVP1 (shown schematically in FIGS. 35, 38 and 39) ofthe blade housing 7800 that bisects the blade housing 7800 andspecifically the central region 7811 of the blade housing mountingsection 7802 and that intersects and is parallel to the blade housingcenter line CBH, while the second split portion 7801 c may be consideredas extending along a vertically extending plane BHVP2 (shownschematically in FIGS. 35 and 39) that intersects and is transverse tothe vertically extending, longitudinal plane BHVP1 of the blade housing7800 and is parallel to the blade housing center line CBH. However, forsake of simplicity, reference will be made to the first and second bladehousing split axes BHSA1, BHSA2.

The first split portion 7801 a is adjacent to and extends through anouter wall 7806 of the mounting section 7802, while the second splitportion 7801 c is adjacent to and extends through the inner wall 7852 ofthe blade support section 7850 and an inner wall 7804 of the mountingsection 7802. Specifically, a proximal end 7801 j of the first splitportion 7801 a extends through the outer wall 7806 of the mountingsection 7802 and a distal end 7801 m of the second split portion 7801 bextends through the inner wall 7852 of the blade support section 7850.The inner wall 7804 of the mounting section 7802 overlies and iscoincident with the inner wall 7852 of the blade support section 7950 inthe region of the mounting section 7802. Thus, the distal end 7801 m ofthe second split portion 7801 b similarly extends through the inner wall7804 of the mounting section 7802.

The first split portion 7801 b extends between the proximal end 7801 jand a distal end 7801 k and the second split portion extends between aproximal end 7801 l and the distal end 7801 m. The distal end 7801 k ofthe first split portion 7801 b and the proximal end 7801 l of the secondsplit portion 7801 c are connected by a short angled transition region7801 t. Accordingly, the blade housing split 7801 may be viewed asextending along and centered about a blade housing split axis BHSA. Theblade housing split axis BHSA is comprised of two intersecting axesBHSA1, BHSA2. As can best be seen in the top plan view of FIG. 36, thefirst, rearward radially extending split portion 7801 b of the split7801 a extends along the first or radial split axis BHSA1. The firstsplit axis BHSA1 extends along the radius line and the verticallongitudinal plane BHVP of the blade housing and intersects the bladehousing center line CBH. The second, forward angled portion 7801 c ofthe split 7801 a extends along the second or linear split axis BHSA2.The second split axis BHSA2 extends along an angled line that istransverse with respect to the first split axis BHSA1. As can be seen inFIG. 36, an acute angle alpha α is formed between the first split axisBHSA1 of the first rearward radially extending blade housing splitportion 7801 b of the split 7801 a and the second split axis BHSA2 ofthe second forward angled blade housing split portion 7801 c of thesplit 7801 a. In one exemplary embodiment, when viewed in plan view,e.g. FIG. 36, the angle alpha α is approximately 15°.

The distal end 7801 m of the second split portion 7801 c at the innerwall 7852 of the blade support section 7850 defines the terminationlocation 7801 h of the split 7801 a. The split 7801 a and, morespecifically, the distal portion 7801 m of the second split portion 7801c extends though the inner wall 7804 of the mounting section 7802 andterminates at a termination location or position 7801 h with respect tothe inner wall 7804. The termination location 7801 h of the second splitportion 7801 c is circumferentially offset from the intersectionlocation 7801 i, that is, the circumferential location of the inner wall7852 of the blade support section 7850 where that the first bladehousing split axis BHSA of the first split portion 7801 b intersects theinner wall 7852 of the blade support section 7850. Recall that in theblade housing 6800 of the sixth exemplary embodiment, the split 6801 aextended along the blade housing split axis BHSA that in essence was aradius line that bisected the central region 6811 of the blade housingmounting section 6850 and intersected and was orthogonal to the bladehousing center line CBH. As such, the blade housing split axis BHSA ofthe blade housing split 6801 of the blade housing 6800 of the sixthexemplary embodiment, when viewed in plan view, essentially bisected ordefined a center line though the pinion gear recess 6815 and the sleevebushing recess 7816 formed in the upper surface 6808 a of the upper end7808 of the mounting section 6802. Therefore, a termination location ofthe split 6801 a was on a radius line defined by the blade housing splitaxis BHSA.

By contrast, in the blade housing 7800 of the seventh exemplaryembodiment, the termination location 7801 h of the split 7801 a at theinner wall 7852 of the blade support section 7850 is circumferentiallyoffset from the intersection position 7801 i of the first blade housingsplit axis BHSA1 at the inner wall 7852 of the blade support section7850. Accordingly, as the first blade housing split axis BHSA1 of thefirst split portion 7801 b of the blade housing split 7801 a, whenviewed in plan view, bisect a pinion gear recess 7815 and a sleevebushing recess 7816 formed in an upper surface 7808 a of an upper end7808 of the mounting section 7802 of the blade housing 7800, thetermination location 7801 h is circumferentially offset from a centerline through the pinion gear recess 7815 and the sleeve bushing recess7816.

The termination location or position 7801 h of the split 7801 acorresponds to the position of circumferential ends 7852 a, 7852 b ofthe inner wall 7852 of the blade support section 7850. The terminationlocation 7801 h of the split 7801 a corresponds to forward end portions7825 a, 7835 a of the facing surfaces 7825, 7835 of the first and secondbody portions 7820, 7830 of the blade housing mounting section 7802.When the blade housing 7800 is in the first, blade supporting position7898, the split distance at the termination position 7801 h between thecircumferential ends 7852 a, 7852 b of the inner wall 7852 of the bladesupport section 7850 (and similarly between the forward end portions7825 a, 7835 a of the facing surfaces 7825, 7835) is split distance D1and when the blade housing 7800 is in the second, blade changingposition 7899, the split distance at the termination position 7801 hbetween the circumferential ends 7852 a, 7852 b of the inner wall 7852of the blade support section 7850 is split distance D2. Stated anotherway, in the first, blade supporting position 7898, the split width orsplit distance at the termination position 7801 h between the forwardend portions 7825 a, 7835 a of the facing surfaces 7825, 7835 is splitdistance D1 and in the second, blade changing position 7899, the splitdistance at the termination position 7801 h between the forward endportions 7825 a, 7835 a of the facing surfaces 7825, 7835 is splitdistance D2.

As explained above, when viewed in plan view, the first blade housingsplit axis BHSA1 may be viewed as a center line through acircumferential extent of the pinion gear and sleeve bushing recesses7815, 7816, that is, substantially parallel to and vertically alignedwith the handle assembly longitudinal axis LA and the pinion gear axisof rotation PGR. A center line through the pinion gear recess 7815 and,more specifically, a region where the gear head 7614 of the pinion gear7610 meshes with the driven gear 7340 of the rotary knife blade 7300represents a gear meshing region 7817 (FIGS. 27 and 30) of the bladehousing 7800. Advantageously, the circumferential offset of thetermination location 7801 h of the split 7801 a from the intersectionposition 7801 i defined by the first blade housing split axis BHSA1 withrespect to the inner wall 7852 of the blade support section 7850mitigates the potential migration of debris from cutting and trimmingoperations into the gear meshing region 7817 where the gear head 7614 ofthe pinion gear 7610 meshes with the driven gear 7340 of the rotaryknife blade 7300. Collecting debris materials in the region 7817 of themeshing of the pinion gear 7610 and the driven gear 7340 of the rotaryknife blade 7300 is undesirable because the heat generated by thedriving engagement tends to “cook” the debris creating a sticky build-upon the pinion gear gear head 7614 and the driven gear 7340 of the rotaryknife blade 7300. Such a build-up of debris may lead to increasedvibration of the power operated rotary knife 7000 during operation andshorten rotary knife blade 7300 and pinion gear life, all of which aredetrimental to rotary knife performance. Stated another way, thetermination position 7801 h of the split 7801 a is advantageously: a)circumferentially offset from the region of the meshing of the piniongear 7610 and the driven gear 7340 of the rotary knife blade 7300; b)circumferentially offset from the intersection location 7801 i definedby the first blade housing split axis BHSA1 of the first split portion7801 b of the split 7801 a where the first blade housing split axisBHSA1 intersects the inner wall 7852 of the blade support section 7850and the inner wall 7804 of the mounting section 7802; c) when viewed inplan view, offset from a radius line RL (shown schematically in FIG. 36)which bisects the pinion gear and sleeve bushing recesses 7815, 7816;and d) when viewed in plan view, offset from the handle assemblylongitudinal axis LA and an axis of rotation PGA of the pinion gear7610.

As best seen in FIGS. 33 and 34, the cam mechanism 7900 secures bladehousing mounting section 7802 of the assembled blade-blade housingcombination 7500 to the frame body mounting pedestal 7272 via a pair ofthreaded fasteners 7900 which extend through cam plate openings 7982 a,7882 b and thread into respective threaded openings 7274 of lowersurface 7270 of forward portion 7251 of the frame body 7250. The pair offasteners 7990 pass through mounting slots 7826, 7836 of first andsecond body portions 7820, 7830 of the mounting section 7802 of theblade housing 7800. Essentially, the blade housing mounting section 7802is sandwiched between the cam mechanism cam plate 7950 and the framebody mounting pedestal 7272. Additionally, as can best be seen in FIGS.36 and 39, a rearward section 7801 d of the first split portion 7801 bincludes a cavity 7801 f adjacent the outer wall 7806 of the mountingportion or section 7802. In the region of the cavity 7801 f, thedistance between the facing surfaces 7825, 7835 of the first and secondbody portions 7820, 7830 is greater than the split distance D1, asmeasured at the inner wall 7852 of the blade support section 7850adjacent the split 7801 a. The cavity 7801 f includes a cylindricalopening 7801 g that receives a cylindrical post or cylindrical boss 7273extending orthogonally downwardly from a planar extent of the mountingpedestal 7272 of the lower surface 7270 of the forward portion 7251 ofthe frame body 7250 when the assembled blade-blade housing combination7500 is secured to the frame body 7250.

The cylindrical opening 7801 g is adjacent the outer wall 7806 of themounting portion or section 7802 and is formed in part by rearward endportions 7825 b, 7835 b of the facing surfaces 7825, 7835 at the outerwall 7806. The facing surface 7825 for the first body portion 7820includes a half cylinder region 7825 a and the facing surface 7835 ofthe second body portion 7830 includes a corresponding aligned halfcylinder region 7835 a, which taken together form the cylindricalopening 7801 g. The cylindrical opening 7801 g extends between andthrough the upper and lower ends 7808, 7810 of the mounting section 7802and a central axis CACO of the cylindrical opening 7801 g intersects thefirst blade housing split axis BHSA1 and is substantially parallel tothe blade housing center line CBH. In the first, blade supportingposition 7898 of the blade housing, a split distance between therearward end portions 7825 b, 7835 b of the facing surfaces 7825, 7835at the outer wall 7806 of the mounting section 7802 is greater than thesplit distance D1 between the forward end portions 7825 a, 7835 a of thefacing surfaces 7825, 7835 at the inner wall 7804 of the mountingsection 7802.

Advantageously, the interfit of the frame body cylindrical boss 7273 andthe cylindrical opening 7801 g during assembly of the assembledblade-blade housing combination 7500 to the frame body 7250 insuresproper alignment of the mounting section 7802 of the blade housing 7800with respect to the frame body mounting pedestal 7272. Additionally, acylindrical side wall 7273 a of the frame body boss 7273 advantageouslyprovides for proper circumferential alignment for the first and secondbody portions 7820, 7830 of the mounting section 7802 as the assembledblade-blade housing combination 7500 is secured to the frame body 7250via the pair of threaded fasteners 7990. That is, the cylindrical sidewall 7273 a abuts the half cylinder region 7825 a of the facing surface7825 of the first body portion 7820 and abuts the half cylinder region7835 a of the facing surface 7835 of the second body portion 7830thereby inhibiting the possibility of circumferential misalignment ofthe forward end portions 7825 a, 7835 a of the facing surfaces 7825,7835 at the inner wall 7804 of the mounting section 7802. Moreover, ascan best be seen in FIG. 42, a pair of longitudinally extendingchamfered or angled recessed portions 7810 b bridge the lower surface7810 a and the outer wall 7806 of the mounting section 7802. The firstbody portion 7820 of the mounting section 7802 includes one of the pairof angled recessed portions 7810 b, while the second body portion 7830includes the second of the pair of angled recessed portions 7810 b. Thepair of angled recessed portions 7810 b of the mounting section 7802interfit with and receive downwardly extending edges 7984 a, 7984 b ofthe cam plate 7950 (best seen in FIGS. 47 and 48). As can be seen inFIG. 27, the interfitting of the downwardly extending edges 7984 a, 7984b into respective ones of the pair of angled portions 7810 b insuresproper alignment of the mounting section 7802 of the blade housing 7800and the cam plate 7950, further facilitates proper alignment of themounting section 7802 of the blade housing 7800 with respect to theframe body mounting pedestal 7272 and further mitigates the possibilityof circumferential misalignment of the forward end portions 7825 a, 7835a of the facing surfaces 7825, 7835 at the inner wall 7804 of themounting section 7802.

An additional visual aid to proper alignment of the mounting section7802 of the blade housing 7800 with respect to the frame body mountingpedestal 7272 results from the matching planar configurations a planarrearward or distal portion 7807 of the outer wall 7806 of the bladehousing mounting section 7802 and the planar side wall 7272 a adjacentto and extending orthogonally with respect to the planar mountingpedestal 7272 of the frame body 7250. During assembly, properorientation of the assembled blade-blade housing combination 7500 withrespect to the frame body mounting pedestal 7272 can be easilyascertained by viewing the orientation and position of the distalportion 7807 of the outer wall 7806 of the blade housing mountingsection 7802 with respect to the respect to the planar side wall 7272 aof the frame body 7250 adjacent the mounting pedestal 7272.

The mounting section 7802 of the blade housing 7800 includes the innerwall 6804, which overlaps and is coincident with the inner wall 7852 ofthe blade support section 7850 and comprises and corresponds to aportion of an inner wall 7800 a of the blade housing 7800, and aradially spaced apart outer wall 7806, which defines a portion of anouter wall 7800 b of the blade housing 7800, and the upper end 7808,which defines a portion of an upper end 7800 c of the blade housing7800, and an axially spaced apart lower end 7810, which defines aportion of a lower end 7800 e of the blade housing 7800. The upper end7808 of the mounting section 7802 defines the generally planar uppersurface 7808 a. An upper end 7856 (defining an upper planar surface 7856a) of the blade support section 7850 and the upper end 7808 (definingthe upper planar surface 7808 a) of the mounting section 7802 areadvantageously coplanar with and together form the planar upper surface7800 d of the blade housing 7800. As noted above, there are first andsecond arcuate recesses 7815, 7816 formed in the planar upper surface7808 a of the upper end 7808 adjacent the inner wall 7800 a of the bladehousing 7800. The first arcuate recess 7815 provides clearance for thegear head 7624 of the pinion gear 7610 such that the pinion gear gearhead 7624 is positioned to engage the mating driven gear 7340 of therotary knife blade 7300 and the second, shallower arcuate recess 7816 ispositioned radially outwardly from and aligned with the first arcuaterecess 7815 and provides clearance for the sleeve bushing 7630 thatsupports the pinion gear 6610 for rotation about the pinion gear axis ofrotation PGR.

The first body portion 7820 of the blade housing central region 7811includes a generally planar upper surface 7821, an axially spaced apart,generally planar lower surface 7822. Because the split 7801 a has adog-leg configuration when viewed in plan view because of secondforwardly extending angled split portion 7801 c, the first body portion7820 is larger than the second body portion 7830 and the first andsecond body portions 7820, 7830 are not symmetric about the split 7801a, as was the case in the first and second body portions 6820, 6830 ofthe blade housing 6800 of the sixth exemplary embodiment. The first bodyportion 7820 also includes an inner surface 7823 forming part of: a) theinner wall 7800 a of the blade housing 7800; b) the inner wall 7804 ofthe mounting section 7802; and c) the coincident inner wall 7852 of theblade support section 7850, and an outer surface 7824 forming part of:a) the outer wall 7800 b of the blade housing 7800; and b) the outerwall 7806 of the mounting section 7802. The second body portion 7830 ofthe blade housing central region 7811 includes a generally planar uppersurface 7831, an axially spaced apart, generally planar lower surface7832. The second body portion 7830 also includes an inner surface 7833forming part of: a) the inner wall 7800 a of the blade housing 7800; b)the inner wall 7804 of the mounting section 7802; and c) the coincidentinner wall 7852 of the blade support section 7850, and an outer surface7834 forming part of: a) the outer wall 7800 b of the blade housing7800; and b) the outer wall 7806 of the mounting section 7802.

As can be seen in FIG. 36, the first body portion 7820 includes thegenerally oval shaped first mounting slot 7826 extending between andthrough the upper and lower surfaces 7821, 7822, while the second bodyportion 7830 includes the generally oval second mounting slot 7836extending between and through the upper and lower surfaces 7831, 7832.Unthreaded shaft portions 7992 of the pair of threaded fasteners 7990 ofthe cam mechanism 7900 pass through the respective mounting slots 7826,7836 of first and second body portions 7820, 7830 of the central region7811 of the mounting section 7802 of the blade housing 7800. As can beseen in FIGS. 27-29 and 33, the unthreaded shaft portions 7992 of thepair of threaded fasteners 7990 are captured in respective cam plateopenings 7982 a, 7982 b of the cam plate 7950 and the enlarged heads7991 of the pair of fasteners 7990 bear against the cam plate 7950. Theunthreaded shaft portions 7992 of the pair of threaded fasteners 7990pass through the respective mounting slots 7826, 7836 of first andsecond body portions 7820, 7830 and the threaded end portions 7993 ofthe pair of fasteners 7990 then thread into respective threaded openings7274 of the planar mount pedestal 7272 of the lower surface 7270 of thefame body 7250 to secure the blade housing 7800 to the frame body 7250.An upper surface 7952 of the cam plate 7950 bears against the planarlower surface 7810 a of the blade housing mounting section 7802,specifically, the planar lower surfaces 7822, 7832 of the first andsecond body portions 7820, 7830 of the blade housing mounting section7802, to urge the planar upper surface 7808 a of the mounting section7802 against the planar mounting pedestal 7272 of the lower surface 7270of the fame body 7250 and secure the blade housing 7800 to the framebody 7250.

As can best be seen in FIGS. 33 and 35, the lower surface 7822 of thefirst body portion 7820 includes a first cam slot 7827 which receivesand constrains a first cam pin 7930 of the cam member 7910 of the cammechanism 7900. The first cam slot 7827 includes a first end portion7827 a and a second end portion 7827 b that is closer to the first splitportion 7801 c. As depicted schematically in FIGS. 35 and 42, the firstcam slot 7827 includes a linear portion 7828 defining a linear path oftravel 7828 a for the first cam pin 7930 and an offset catch portion7829. The first cam slot 7827 is transverse to the first blade housingsplit axis BHSA1 and the second blade housing split axis BHSA2 and, ifextended along the linear path of travel 7828 a, would intersect theblade housing split 7801 a and the first and second blade housing splitaxes BHSA1, BHSA2. The lower surface 7832 of the second body portion7830 includes a second cam slot 7837 which receives and constrains asecond cam pin 7932 of the cam member 7910 of the cam mechanism 7900.The second cam slot 7837 includes a first end portion 7837 a and asecond end portion 7837 b that is closer to the split 7801 a. The secondcam slot 7837 includes a linear portion 7838 defining a linear path oftravel 7838 a for the second cam pin 7930 and an offset catch portion7829. The second cam slot 7827 is transverse to the first blade housingsplit axis BHSA1 and the second blade housing split axis BHSA2 and, ifextended along the linear path of travel 7838 a, would intersect theblade housing split 7801 a and the first and second blade housing splitaxes BHSA1, BHSA2.

As is schematically depicted in FIG. 42, in the first, closed position7998 of the cam mechanism 7900, the first cam pin 7930 is positioned orlocated nearer the first end portion 7827 a of the first cam slot 7827and the second cam pin 7932 is positioned or located nearer the firstend portion 7837 a of the second cam slot 7837. In one exemplaryembodiment, the first cam pin 7930 is positioned at the first endportion 7827 a of the first cam slot 7827 and the second cam pin 7932 ispositioned at the first end portion 7837 a of the second cam slot 7837.Also, in the first, closed position 7998 of the cam mechanism 7900, theunthreaded shaft portions 7992 of the pair of fasteners 7990 arepositioned in proximity to or adjacent respective first ends 7826 a,7836 a of the blade housing mounting slots 7826, 7836. As the cam member7910 is rotated to the second, open position 7999, the first and secondcam pins 7930, 7932 move or translate within their respective first andsecond cam slots 7827, 7837 along the respective linear paths of travel7928 a, 7938 a to positions or locations nearer the respective secondend portions 7827 b, 7837 b of the cam slots 7827, 7837, coming to restin the respective offset catch portions 7829, 7839. This movement ortranslation of the first and second cam pins 7930, 7932 within theirrespective first and second cam slots 7827, 7837 from the respectivefirst end portions 7827 a, 7837 a to the respective second end portions7827 b, 7837 b forces, by camming action, an expansion of the bladehousing diameter from the unexpanded blade housing diameter BHD1,corresponding to the first, blade supporting position 7898 of the bladehousing 7800, to the expanded blade housing diameter BHD2, correspondingto the second, blade changing position 7899 of the blade housing 7800,allowing for easy removal of the annular rotary knife blade 7300 fromthe blade housing blade support section 7850. Further, as the first andsecond body portions 7820, 7830 of the blade housing mounting section7802 move apart or spreads circumferentially along the blade housingsplit 7801 a such that the blade housing diameter moves from theunexpanded blade housing diameter BHD1 to the expanded blade housingdiameter BHD2, the unthreaded shaft portions 7992 of the pair offasteners 7990 are now in proximity to or adjacent respective secondends 7826 b, 7836 b of the blade housing mounting slots 7826, 7836.

Conversely, as schematically depicted in FIG. 44, as the cam member 7910is rotated from the second, open position 7999 to the first, closedposition 7998, the first and second cam pins 7930, 7932 move ortranslate within their respective first and second cam slots 7827, 7837along the respective linear paths of travel 7928 a, 7938 a to positionsnearer the respective first end portions 7827 a, 7837 a. This movementor translation of the first and second cam pins 7930, 7932 within theirrespective first and second cam slots 7827, 7837 from the respectivesecond end portions 7827 b, 7837 b to the respective first end portions7827 a, 7837 a allows the blade housing 7800, which is resilientlydeformable and has the unexpanded blade housing diameter BHD1 as itsnatural, undeformed condition, by camming action, to return from theexpanded blade housing diameter BHD2 to the unexpanded blade housingdiameter BHD1. Further, as the blade housing mounting section 7802 movescircumferentially to return to its unexpanded blade housing diameterBHD1, the unthreaded shaft portions 7992 of the pair of fasteners 7990are once again in proximity to or adjacent respective first ends 7826 a,7836 a of the blade housing mounting slots 7826, 7836. Further, asexplained above with respect to the cam mechanism 6900 of the sixthexemplary embodiment, since the cam member 7910 is always set at thespecific predetermined rotational orientation with respect to the camplate 7950 and the blade housing mounting section 7802, the position ofthe cam member pins 7930, 7932 of the cam member 7910 are set aspecific, predetermined and repeatable locations within their respectivecam slots 7827, 7837. That is, because of the bearing of centralportions 7973 a, 7973 b of the retainer springs 7972 a, 7972 b in thefirst, closed position 7998 of the blade housing 7800 against respectiveflat areas 7924 a, 7924 b of the cam member 7910, the position orlocation of the cam member pin 7930 at the first end 7827 b of the camslot 7827 of the first body portion 7920 of the blade housing mountingsection or portion 7802 and the position of the cam member pin 7932 atthe first end 7837 b of the cam slot 7837 of the first body portion 7930of the blade housing mounting section 7802 is set precisely,consistently and reproducibly each time the cam member 7910 is rotatedto the first, closed position 7999. The precise and reproduciblepositioning of the cam member pins 7930, 7932 within their respectivecam slots 7927, 7937 resulting from the engagement of the cam plateretainer springs 7972 a, 7972 b against the respective planar or flatareas 7924 a, 7925 b of the recessed regions 7920 a, 7920 b of the sidewall 7918 of the cam member 7910 when the blade housing 7800 is in thefirst, blade supporting position 7898 functions to move the mountingsection 7802 of the blade housing 7800 into the same position orconfiguration every time the cam member 7910 is rotated to its first,closed position 7998.

The blade support section 7850 of the blade housing 7800 is similar andfunction to the blade support section 6850 of the blade housing 6800 ofthe sixth exemplary embodiment. The inner wall 7852 of the blade supportsection 7850 defines the bearing region 7860 of the blade housing 7800.The bearing region 7860 of the blade support section 7850 includes abearing race 7866 comprising the arcuate first bearing surface 7862 anda bearing bead 7880 comprising a second bearing surface 7882 of thebearing region 7860. The bearing region 7860 of the blade housing 7800engages a bearing region 7320 of the body 7310 of the rotary knife blade7300 to support the blade 7300 for rotation about the central axis ofrotation R. The inner wall 7852 of the blade support section 7850defines a blade housing central opening BHCO (FIG. 36) and is centeredabout and defines the blade housing center line CBH. The blade housingcenter line CBH, in the first, blade supporting position 7898 of theblade housing 7800, is substantially coincident with the blade centralaxis of rotation R. In the second, blade changing position 7899 of theblade housing 7800, the inner wall 7852 of the blade support section6850 takes on a very slight oval or egg-shaped configuration because ofthe larger split distance D2.

In one exemplary embodiment, the thickness or depth of the blade housing7800 is substantially uniform (ignoring the pinion gear and sleevebushing recesses 7815, 7816 and the first and second cam slots 7827,7837) along the entirety of the blade housing 7800 and is approximately0.21 in. In one exemplary embodiment, a longitudinal extent of themounting section 7802, as measured along the first blade housing splitaxis BHSA1, is approximately 0.53 in. A total width of the centralregion of the mounting section 7802, in the blade supporting position7898 of the blade housing 7800, in one exemplary embodiment, isapproximately 1.59 in. In one exemplary embodiment, the blade housingsplit distance D1 corresponding to the first, blade supporting position7898 of the blade housing 7800, as measured at the inner wall 7852 ofthe blade support section 7850 in a direction parallel to the firstblade housing split axis BHSA1 and the radius line RL and as shown inFIG. 36, is approximately 0.01 in., while the blade housing splitdistance D2 corresponding to the second, blade changing position 7899 ofthe blade housing 7800 is approximately 0.36 in. (FIG. 43). As best seenin the plan view of FIGS. 36 and 39, it should be understood that asplit perpendicular width or split width, as measured orthogonally orperpendicularly with respect to the split axis BHSA between opposingfaces 7825, 7835 will vary in other portions of the split 7801 a. Forexample, in the first radial split portion 7801 b, as measuredorthogonally with respect to the first split axis BHSA1, the splitperpendicular width between opposing faces 7825, 7835 is variable inmoving along the first split axis BHSA1 from the rearward portion 7801 dto the forward portion 7801 e of the first radial split portion 7801 b.In the second angled split portion 7801 c, a split perpendicular widthor split width, as measured orthogonally or perpendicularly with respectto the second split axis BHSA2, between opposing faces 7825, 7835 isboth small and substantially constant or uniform in moving along thesecond split axis BHSA2 from the rearward portion 7801 l to the forwardportion 7801 m of the second angled split portion 7801 c. The annularrotary knife blade 7300, when viewed in top plan view (e.g., FIG. 36),rotates in a counterclockwise direction. Advantageously, in the bladesupporting position 7898 of the blade housing 7800 and given therotational direction of the rotary knife blade 7300: a) the small valueof the split distance D1 at the inner wall 7852 of the blade supportsection 7850; b) the small and constant value of the split width of thesecond, angled split portion 7801 c between opposing faces 7825, 7835;and c) the angled orientation of the second, angled split portion 7801 cas it extends though the blade support section inner wall 7852, combineto inhibit the entry of debris (resulting from cutting and trimmingoperations) into the second, angled split portion 7801 c at thetermination location 7801 h and mitigate potential migration of debrisrearwardly along the split 7801 a. In one exemplary embodiment, theblade housing outer diameter BHD1 corresponding to the first, bladesupporting position 7898 of the blade housing 6800 is approximately 2.08in., while the blade housing outer diameter BHD2 corresponding to thesecond, blade changing position 7899 of the blade housing isapproximately 2.17 in. As noted previously, it is understood, that thesedimensions will necessarily change based on the size and configuration,characteristics and parameters of the rotary knife blade to be supportedby the blade housing, the blade-blade housing bearing structure, andother parameters and characteristics of the power operated rotary knife7000 and components thereof.

Cam Mechanism 7900

As best seen in FIGS. 40-41 and 44-48, the cam mechanism 7900 includes acam member 7910 and a cam plate 7950 that support the cam member 7910for rotation about a cam member axis of rotation CMA, which issubstantially parallel to the blade housing center line CBH. As notedpreviously, advantageously, the cam mechanism 7900 functions both to: a)secure the assembled blade-blade housing combination 7500 to the framebody 7250; and b) as desired, allows an operator or maintenance personto selectively change the diameter of the blade support section 7850 ofthe blade housing 7800 between the first, unexpanded blade housingdiameter BHD1 (for purposes of supporting the rotary knife blade 7300for rotation about the central axis of rotation R during use of thepower operated rotary knife 7000) and the second, expanded blade housingdiameter BHD2 (for purposes of removing the rotary knife blade 7300 fromthe blade housing 7800 for purposes of sharpening, blade changing,cleaning and/or maintenance of the power operated rotary knife 7000).

As compared to the cam mechanism 6900 of the blade housing assembly6700, the cam mechanism 7900 of the blade housing assembly 7700 haschanges to both the cam member 7910 and the cam plate 7950. The cammechanism 7900 is intended to be used with a range of split bladehousings sizes and a range of rotary knife blade housing sizes. That is,the same cam mechanism 7900 may be utilized with smaller diameter splitblade housings suitable for rotatably supporting rotary knife bladesthat are of smaller diameter, e.g., 2 inches in outer diameter, as wellas utilized with larger diameter split blade housings suitable forrotatably supporting rotary knife blades that are of larger diameter,e.g., 7 inches in outer diameter. Specifically, with respect to the cammember 7910, the cam member 7910 comprises a generally rectangular base7912 defined by a side wall 7918 and generally planar upper and lowersurfaces 7914, 7916. In the rectangular base 6912 of the cam member7910, each of the four corners formed by the side wall 6918 weresubstantially identical, rounded corners. However, to provide additionalclearance necessary for use of the cam mechanism with larger diameterrotary knife blades and corresponding larger diameter blade housings, acorner region 7912 a of the rectangular base 7912 is truncated orangled, as best seen in FIGS. 35, 42 and 43 thereby providing foradditional clearance between the truncated corner region 7912 a and therotary knife blade 7300 when the cam member 7910 is rotated to thesecond, unlocked position 7999 of the cam mechanism 7900.

Additionally, to improve manufacturing efficiency and manufacturabilityof the cam mechanism 7900, in the cam mechanism 7900 of the seventhexemplary embodiment, the rotation limitation tab 7937 is formed on thecam member 7910 and the interfitting arcuate slot 7977 which receivesthe tab 7937 is formed on the cam plate 7950. In the cam mechanism 6900of the sixth exemplary embodiment, the tab 6978 of the cam plate 6950extended into the arcuate notch 6938 of the boss 6934 of the cam member6910. Thus, an arcuate or rotational path of travel RPOT of the cammember 6920 with respect to the cam plate 6950 was necessarily limitedby the arcuate or circumferential extent of the arcuate notch 6938. Inthe cam mechanism, the same rotation limitation functionality exits,however, manufacturing efficiency favors fabrication of the rotationlimitation tab 7937 on the cam member 7910 and fabrication of thearcuate slot 7977 on the cam plate 7950, as described below.

As best seen in FIGS. 39 and 41, the cam plate 7950 of the cam mechanism7900 is generally rectangular in plan view and includes an upper surface7952 and a spaced apart generally planar lower surface 7954. The upperand lower surfaces 7952, 7954 are spaced apart by a front side 7956,facing toward the annular rotary knife blade 7300, and a back side 7958,facing toward the handle assembly 7110. Extending between the front andback sides 7956, 7958 of the cam plate 7950 are first and second lateralsides 7960, 7962. The upper surface 7952 of the cam plate 7950 includesgenerally rectangular recess 7964 that receives and supports the cammember 7910. Positioned on either side of the recess 7964 are flankingportions 7980 of the cam plate 7950 that extend a full width or distancebetween the upper and lower surfaces 7952, 7954. The upper surfacerecess 7964 defines a seating region 7966 for the cam member 7910. Therecess 7964 extends through the front and back sides 7956, 7958 of thecam plate 7950. The recess 7964 is defined by a planar lower wall 7967and two side walls 7968 a, 7968 b that extend from the front side 7956to the back side 7958 of the cam plate 7950. The planar lower wall 7967of the recess 7964 is generally parallel to and intermediate between theupper and lower surfaces 7952, 7954 of the cam plate. A centrallylocated opening 7974 extends through lower surface 7954 of the cam plate7950 and intersects the recess 7964, passing though the planar lowerwall 7967 of the recess 7964. As explained above and as best seen inFIGS. 47 and 48, the lower surface 7954 of the cam plate 7950 adjacentthe lateral sides 7960, 7962 includes downwardly extending edges 7984 a,7984 b which interfit into respective angled recessed portions 7810 b ofthe blade housing mounting section 7802.

As best seen in FIGS. 44-46, the cam member 7910 includes a generallyrectangular base 7912 having a generally planar upper surface 7914 and agenerally planar lower surface 7916 separated by the circumferentiallyextending side wall 7918. The upper surface 7914 includes a slot 7944which aids in the assembly of the cam mechanism 7900 by allowing foreasy rotation of the cam member 7910 during assembly. A pair ofopposite, diagonally spaced apart portions 7919 a, 7919 b of the sidewall 7918 include recessed regions 7920 a, 7920 b. The recessed regions7920 a, 7920 b define respective ledges 7922 a, 7922 b which receive andbear against the pair of retainer springs 7972 a, 7972 b of the camplate 7950 to maintain the cam member 7910 within the recess 7964 of thecam plate 7950 as the cam member 7910 is rotated between its first andsecond positions 7998, 7999. The recessed regions 7920 a, 7920 b of theside wall 7918 of the cam member base 7912 also include respectiveplanar or flat areas 7924 a, 7924 b. The planar or flat areas 7924 a,7924 b of the side wall 7918 are spaced 180° apart as viewed in bottomplan view (FIG. 41), are substantially parallel and equidistant from thecam member axis of rotation CMA, and are located near respective endportions of the recessed regions 7920 a, 7920 b. Advantageously, in thefirst, closed position 7998 of blade housing 7800, the planar or flatareas 7924 a, 7924 b bear against respective ones of the pair ofretainer springs 7972 a, 7972 b of the cam plate 7950 set in outwardlybowed portions 7970 a, 7970 b of the side walls 7968 a, 7968 b of therecess 7964 in the upper surface 7952 of the cam plate 7950. As notedpreviously, as the cam member 7910 is rotated about the cam member axisof rotation CMA to the first, closed position 7999 (show schematicallyin FIG. 40), the bearing of the flat areas 7924 a, 7924 b of the sidewall 7918 of the cam member 7910 against the retainer springs 7972 a,7972 b causes the cam member 7910 to be set at a specific precise andrepeatable rotational orientation and, therefore, the mounting section7802 of the blade housing 7800 is precisely and repeatably moved to thesame position or configuration in the first, blade supporting position7898 such that the split distance at the termination position 7801 h issplit distance D1.

As can be seen in FIG. 44-48, the central opening 7974 of the recess7964 of the cam plate 7950 receives an upper cylindrical portion 7935 ofa downwardly extending boss 7934 of the cam member 7910. A center lineCLO through the central opening 7974 defines and is coincident with thecam member axis of rotation CMA. An inner wall 7976 defines the centralopening 6974 of the cam plate 7950 and includes an arcuate notch 7977.The cam member 7910 includes a radially outwardly extending rotationlimitation tab 7937 that interfits within the arcuate notch 7977 of theinner wall 7976 to limit rotation of the cam member 7910 with respect tothe cam plate 7950. Specifically, the upper cylindrical portion 7935 ofthe downwardly extending boss 7934 of the cam member 7910 includes theradially outwardly extending rotation limitation tab 7937.

Advantageously, the rotation limitation tab 7937 of the cam member 7910is received in the cut out or arcuate notch 7977 in the inner wall 7976of the cam plate 7950 to limit rotation of the cam member 6910 withrespect to the cam plate 6950. That is, because the tab 7937 of the cammember 7910 extends into the arcuate notch 7877 of the cam plate 7950,an arcuate or rotational path of travel RPOT of the cam member 7910 withrespect to the cam plate 7950 is necessarily limited by the arcuate orcircumferential extent of the arcuate notch 7877 of the cam plate 7950.When viewed in bottom plan view as shown, for example, in FIGS. 34-35,43 and 44, rotation of the cam member 6910 in the counterclockwisedirection CCW (FIG. 34) (which would be a clockwise direction if viewedin top plan view, e.g., FIG. 36) is limited by the abutment of the firstend 7877 a of the arcuate notch 7977 of the cam plate 7950 and theprotruding tab 7937 of the cam member 7910. Accordingly, in rotating thecam member 7910 from the second, open position 7999 (FIG. 41) to thefirst, closed position 7998 (FIG. 40), the engagement of the tab 7937and the first end 7877 a of the arcuate notch 7877 prevents overrotation of the cam member 7910. Rotation of the cam member 7910 in theclockwise direction from the first, closed position 7998 (FIG. 40) tothe second, open position 7999 (FIG. 41) is limited by: a) theengagement of the first and second cam pins 7930, 7932 within therespective offset catch portions 7829, 7839 of the first and second camslots 7827, 7837 of the first and second body portions 7920, 7930 of theblade housing mounting section 7802; and/or b) the abutment of the firstand second fasteners 7990 of the cam mechanism 7900 with the second endportions 7826 b, 7836 b of the blade housing mounting slots 7826, 7836.During assembly of the cam member 7910 to the cam plate 7910 ordisassembly of the cam member 7910 from the cam plate 7910, the abutmentof the opposite or second end 7977 b of the notch 7977 of the cam plate7950 and the protruding tab 7937 of the cam member 7910 advantageouslyprevent over rotation of the cam member 7910 in the clockwise direction.Over rotation of the cam member 7910 with respect to the cam plate 7950in the clockwise direction during assembly could result in the cammember rectangular base 7912 pushing against and permanently bending ordeforming the pair of retainer springs 7972 a, 7972 b of the cam plate7950. In one exemplary embodiment, the rotational path of travel RPOT ofthe cam member 6930 in moving between the first, closed position 7998and the second, open position 7999 is approximately 45°.

Frame Body 7250

The frame body 7250 of the head assembly 7200 of the power operatedrotary knife 7000 is similar in structure and function to the frame body6250 of the head assembly 6200 of the power operated rotary knife 6000of the sixth embodiment. As noted above and as best seen in FIGS. 26-30and 32-35, the frame body 7250 includes the forward or distal portion7251, which supports the blade housing assembly 7700, and the rearwardor proximal portion 7280, extending in the rearward direction RW towardthe handle assembly 7110. The forward portion 7251 of the frame body7250 includes the mounting pedestal 7272 of the lower surface 7270which, as explained previously, functions as a mounting surface for theblade housing mounting section 7802 and includes the pair of threadedopenings 7274 that receive respective ones of the threaded fasteners7990 of the cam mechanism 7900 thereby urging the cam plate 7950 againstthe planar lower surface 7810 a of the lower end 7810 of the mountingsection 7802. This secures the blade housing mounting section 7802 tothe mounting pedestal 7272 of the frame body 7250 and thereby securesthe blade-blade housing combination 7500, including the cam mechanism7900 which is part of the blade housing assembly 7700, to the frame body7250. The forward portion 7251 of the frame body 7250 additionallyreceives and removably supports a pinion gear shield 7297. The piniongear shield 7297 helps locate the pinion gear 7610 and the sleevebushing 7630 of the drive mechanism 7600 such that the pinion gear 7610operatively engages the driven gear 7340 of the annular rotary knifeblade 7300 to rotate the knife blade 7300 with respect to the bladehousing 7800 about the axis of rotation R in the gear meshing region7817. The pinion gear shield 7297 is secured to a planar mountingsurface 7252 a of a forward wall 7252 of the forward portion 7251 of theframe body 7250 by a pair of threaded fasteners 7299 a.

As explained above, to improve and facilitate alignment during theassembly of the blade-blade housing combination 7500 to the planarmounting pedestal 7272, the mounting pedestal 7272 includes thecylindrical post or cylindrical boss 7273 extending orthogonally from aplanar extent of the mounting pedestal 7272. The cylindrical boss 7272is received in the cylindrical opening 7801 g in the first, rearwardradial split portion 7801 b of the blade housing expansion split 7801 ain the mounting section 7802 of the split blade housing 7800. Thecylindrical opening 7801 g is disposed between facing surfaces 7825,7835 of the first and second body portions 7820, 7830 adjacent therearward end portions 7825 b, 7835 b of the facing surfaces 7825, 7835and the outer wall 7806 of the mounting section 7802, as explainedpreviously. Additionally, as explained above, adjacent to and extendingorthogonally with respect to the planar mounting pedestal 7272 of theframe body 7250 is the planar side wall, which aids in alignment due tomatching planar configurations of the planar distal portion 7807 of theouter wall 7806 of the blade housing mounting section 7802.

As used herein, terms of orientation and/or direction such as front,rear, forward, rearward, distal, proximal, distally, proximally, upper,lower, inward, outward, inwardly, outwardly, horizontal, horizontally,vertical, vertically, axial, radial, longitudinal, axially, radially,longitudinally, etc., are provided for convenience purposes and relategenerally to the orientation shown in the Figures and/or discussed inthe Detailed Description. Such orientation/direction terms are notintended to limit the scope of the present disclosure, this application,and/or the invention or inventions described therein, and/or any of theclaims appended hereto. Further, as used herein, the terms comprise,comprises, and comprising are taken to specify the presence of statedfeatures, elements, integers, steps or components, but do not precludethe presence or addition of one or more other features, elements,integers, steps or components.

What have been described above are examples of the presentdisclosure/invention. It is, of course, not possible to describe everyconceivable combination of components, assemblies, or methodologies forpurposes of describing the present disclosure/invention, but one ofordinary skill in the art will recognize that many further combinationsand permutations of the present disclosure/invention are possible.Accordingly, the present disclosure/invention is intended to embrace allsuch alterations, modifications, and variations that fall within thespirit and scope of the appended claims.

What is claimed is:
 1. A blade housing assembly for supporting anannular rotary knife blade of a power operated rotary knife for rotationabout a central axis of rotation, the blade housing assembly comprising:a split blade housing including: an annular blade support sectioncentered about a blade housing center line and including an inner wall;a mounting section extending from the blade support section; and a splitextending through the mounting section and the inner wall of the bladesupport section and defining a split distance between first and secondcircumferential ends of the inner wall; the mounting section including afirst body portion and a second body portion on opposite sides of thesplit, the first body portion including a first cam slot having a firstend portion and a spaced apart second end portion; and a cam mechanismincluding: a cam plate bridging the first and second body portions ofthe mounting section of the split blade housing; and a cam memberrotatably supported by the cam plate, the cam member rotatable between afirst, closed position and a second, open position and including a firstcam pin received in the first cam slot of the first body portion of themounting section of the split blade housing, in the first, closedposition of the cam member, the first cam pin is positioned nearer thefirst end portion of the first cam slot and the split distance betweenthe first and second circumferential ends of the inner wall being afirst value, in the second, open position of the cam member, the firstcam pin is positioned nearer the second end portion of the first camslot and the split distance between the first and second circumferentialends of the inner wall being a second value.
 2. The blade housingassembly of claim 1 wherein the first body portion of the mountingsection includes a first surface and an axially spaced apart secondsurface, the second surface including the first cam slot and furtherwherein the cam member includes a base and the first cam pin extendsfrom a first surface of the base.
 3. The blade housing assembly of claim1 wherein the second value of the split distance between the first andsecond circumferential ends of the inner wall is greater than the firstvalue and the first value of the split distance between the first andsecond circumferential ends of the inner wall corresponding to a first,blade supporting position of the split blade housing and the secondvalue of the split distance between the first and second circumferentialends of the inner wall corresponding to a second, blade changingposition of the split blade housing.
 4. The blade housing assembly ofclaim 1 wherein the second end portion of the first cam slot is closerto the first split portion of the split than the first end portion ofthe first cam slot and, in the first, closed position of the cam member,the first cam pin is positioned at the first end portion of the firstcam slot and, in the second, open position of the cam member, the firstcam pin is positioned at the second end portion of the first cam slot.5. The blade housing assembly of claim 1 wherein the cam plate includesan opening extending through the cam plate and the base of the cammember includes a first surface and an axially spaced apart secondsurface and a boss extending from the second surface and rotatablyreceived in the opening of the cam plate, the boss including an actuatorfor rotating the cam member between the first, closed position and thesecond, open position.
 6. The blade housing assembly of claim 1 whereinthe second body portion of the mounting section of the blade housingincludes a first surface and an axially spaced apart second surface, thesecond surface including a second cam slot having a first end portionand a spaced apart second end portion and further wherein the cam memberincludes a second cam pin received in the second cam slot of the secondbody portion of the mounting section of the split blade housing, in thefirst, closed position of the cam member, the second cam pin ispositioned nearer the first end portion of the second cam slot and inthe second, open position of the cam member, the second cam pin ispositioned nearer the second end portion of the second cam slot.
 7. Theblade housing assembly of claim 1 wherein the mounting section of thesplit blade housing includes an inner wall and an outer wall and thesplit extending through the body portion includes a first split portionadjacent the outer wall of the mounting section and a second splitportion adjacent the inner wall of the mounting section, the secondsplit portion extending transversely with respect to the first splitportion.
 8. The blade housing assembly of claim 7 wherein the firstsplit portion extends along a first blade housing split axis whichintersects the blade housing center line and the second split portionextends along a second blade housing split axis, the first and secondblade housing split axes intersecting.
 9. The blade housing assembly ofclaim 8 wherein the first blade housing split axis of the first splitportion intersects the inner wall of the blade support section at anintersection location and the second split portion extends through theinner wall of the blade support section at a termination location thatis circumferentially offset the intersection location.
 10. A bladehousing assembly for supporting an annular rotary knife blade of a poweroperated rotary knife for rotation about a central axis of rotation, theblade housing assembly comprising: a split blade housing including: anannular blade support section centered about a blade housing centerline, an inner wall of the blade support section defining a bladebearing region; a mounting section extending from the blade supportsection; and a split extending through the mounting section and theinner wall of the blade support section and defining a split distancebetween first and second circumferential ends of the inner wall; themounting section including a first body portion and a second bodyportion on opposite sides of the split, the first body portion includinga first cam slot having a first end portion and a spaced apart secondend portion and the second body portion including a second cam slothaving a first end portion and a spaced apart second end portion; and acam mechanism including: a cam plate bridging the first and second bodyportions of the mounting section of the split blade housing; and a cammember rotatably supported by the cam plate, the cam member rotatablebetween a first, closed position and a second, open position andincluding a first cam pin received in the first cam slot of the firstbody portion of the mounting section of the split blade housing and asecond cam pin received in the second cam slot of the second bodyportion of the mounting section of the split blade housing, in thefirst, closed position of the cam member, the first cam pin ispositioned nearer the first end portion of the first cam slot, thesecond cam pin is positioned nearer the first end portion of the secondcam slot and the split distance between the first and secondcircumferential ends of the inner wall being a first value, in thesecond, open position of the cam member, the first cam pin is positionednearer the second end portion of the first cam slot, the second cam pinis positioned nearer the second end portion of the second cam slot andthe split distance between the first and second circumferential ends ofthe inner wall being a second value.
 11. The blade housing assembly ofclaim 10 wherein the mounting section includes an inner wall and anouter wall and the split extending through the body portion includes afirst split portion adjacent the outer wall of the mounting section anda second split portion adjacent the inner wall of the mounting section,the second split portion extending transversely with respect to thefirst split portion.
 12. The blade housing assembly of claim 11 whereinthe first split portion extends along a first blade housing split axiswhich intersects the blade housing center line and the second splitportion extends along a second blade housing split axis, the first andsecond blade housing split axes intersecting.
 13. The blade housingassembly of claim 12 wherein the first blade housing split axis of thefirst split portion intersects the inner wall of the blade supportsection at an intersection location and the second split portion extendsthrough the inner wall of the blade support section at a terminationlocation that is circumferentially offset the intersection location. 14.The power operated rotary knife of claim 13 wherein the mountingpedestal of the frame body further includes a boss extending from agenerally planar surface of the mounting pedestal and the splitextending through the mounting section of the blade housing defining anopening, the opening of the split sized to receive the boss of themounting pedestal as the cam mechanism secures the mounting section ofthe split blade housing to the mounting pedestal of the frame body. 15.The power operated rotary knife of claim 14 wherein the boss of themounting pedestal and the opening of the split extending through themounting section are both cylindrical.
 16. The power operated rotaryknife of claim 13 wherein the mounting section of the split bladehousing includes an inner wall and an outer wall and the split extendingthrough the body portion includes a first split portion adjacent theouter wall of the mounting section and extending along a first bladehousing split axis and a second split portion adjacent the inner wall ofthe mounting section and extending along a second blade housing splitaxis, the second split portion extending transversely with respect tothe first split portion and the first and second blade housing splitaxes intersecting.
 17. The blade housing assembly of claim 16 whereinthe first blade housing split axis of the first split portion intersectsthe inner wall of the blade support section at an intersection locationand the second split portion extends through the inner wall of the bladesupport section at a termination location that is circumferentiallyoffset the intersection location.
 18. The blade housing assembly ofclaim 10 wherein the second value of the split distance between thefirst and second circumferential ends of the inner wall is greater thanthe first value and the first value of the split distance between thefirst and second circumferential ends of the inner wall corresponding toa first, blade supporting position of the split blade housing and thesecond value of the split distance between the first and secondcircumferential ends of the inner wall corresponding to a second, bladechanging position of the split blade housing.
 19. A power operatedrotary knife comprising: an annular rotary knife blade supported forrotation about a central axis of rotation; an elongated handle assemblyextending along a longitudinal axis; a frame body coupled to a distalend of the elongated handle assembly, the frame body including amounting pedestal; and a blade housing assembly coupled to the framebody and supporting the annular rotary knife blade for rotation aboutthe central axis of rotation, the blade housing assembly including: asplit blade housing including: an annular blade support section centeredabout a blade housing center line and including an inner wall; amounting section extending from the blade support section; and a splitextending through the mounting section and the inner wall of the bladesupport section and defining a split distance between first and secondcircumferential ends of the inner wall; the mounting section including afirst body portion and a second body portion on opposite sides of thesplit, the first body portion including a first cam slot having a firstend portion and a spaced apart second end portion; and a cam mechanismincluding: a cam plate bridging the first and second body portions ofthe mounting section of the split blade housing; and a cam memberrotatably supported by the cam plate, the cam member rotatable between afirst, closed position and a second, open position and including a firstcam pin received in the first cam slot of the first body portion of themounting section of the split blade housing, in the first, closedposition of the cam member, the first cam pin is positioned nearer thefirst end portion of the first cam slot and the split distance betweenthe first and second circumferential ends of the inner wall being afirst value, in the second, open position of the cam member, the firstcam pin is positioned nearer the second end portion of the first camslot and the split distance between the first and second circumferentialends of the inner wall being a second value, the cam mechanism securingthe mounting section of the split blade housing to the mounting pedestalof the frame body.
 20. The power operated rotary knife of claim 19wherein the mounting pedestal of the frame body further includes firstand second threaded openings and the cam mechanism further includesfirst and second threaded fasteners and the cam plate includes a firstopening and a second opening, the first body portion of the split bladehousing including a first mounting slot and the second body portion ofthe split blade housing including a second mounting slot and wherein thefirst fastener extends through the first opening of the cam plate andextends through the first mounting slot of the first body portion of thesplit blade housing and threads into the first threaded opening of themounting pedestal of the frame body and the second fastener extendsthrough the second opening of the cam plate and extends through thesecond mounting slot of the second body portion of the split bladehousing to secure the cam mechanism and the split blade housing to theframe body.